Manual Pages¶

rndc.conf - rndc configuration file¶

Synopsis¶

rndc.conf

Description¶

rndc.conf is the configuration file for rndc, the BIND 9 name server control utility. This file has a similar structure and syntax to named.conf. Statements are enclosed in braces and terminated with a semi-colon. Clauses in the statements are also semi-colon terminated. The usual comment styles are supported:

C style: /* */

C++ style: // to end of line

Unix style: # to end of line

rndc.conf is much simpler than named.conf. The file uses three statements: an options statement, a server statement and a key statement.

The options statement contains five clauses. The default-server clause is followed by the name or address of a name server. This host will be used when no name server is given as an argument to rndc. The default-key clause is followed by the name of a key which is identified by a key statement. If no keyid is provided on the rndc command line, and no key clause is found in a matching server statement, this default key will be used to authenticate the server’s commands and responses. The default-port clause is followed by the port to connect to on the remote name server. If no port option is provided on the rndc command line, and no port clause is found in a matching server statement, this default port will be used to connect. The default-source-address and default-source-address-v6 clauses which can be used to set the IPv4 and IPv6 source addresses respectively.

After the server keyword, the server statement includes a string which is the hostname or address for a name server. The statement has three possible clauses: key, port and addresses. The key name must match the name of a key statement in the file. The port number specifies the port to connect to. If an addresses clause is supplied these addresses will be used instead of the server name. Each address can take an optional port. If an source-address or source-address-v6 of supplied then these will be used to specify the IPv4 and IPv6 source addresses respectively.

The key statement begins with an identifying string, the name of the key. The statement has two clauses. algorithm identifies the authentication algorithm for rndc to use; currently only HMAC-MD5 (for compatibility), HMAC-SHA1, HMAC-SHA224, HMAC-SHA256 (default), HMAC-SHA384 and HMAC-SHA512 are supported. This is followed by a secret clause which contains the base-64 encoding of the algorithm’s authentication key. The base-64 string is enclosed in double quotes.

There are two common ways to generate the base-64 string for the secret. The BIND 9 program rndc-confgen can be used to generate a random key, or the mmencode program, also known as mimencode, can be used to generate a base-64 string from known input. mmencode does not ship with BIND 9 but is available on many systems. See the EXAMPLE section for sample command lines for each.

Example¶

options {
  default-server  localhost;
  default-key     samplekey;
};

server localhost {
  key             samplekey;
};

server testserver {
  key     testkey;
  addresses   { localhost port 5353; };
};

key samplekey {
  algorithm       hmac-sha256;
  secret          "6FMfj43Osz4lyb24OIe2iGEz9lf1llJO+lz";
};

key testkey {
  algorithm   hmac-sha256;
  secret      "R3HI8P6BKw9ZwXwN3VZKuQ==";
};

In the above example, rndc will by default use the server at localhost (127.0.0.1) and the key called samplekey. Commands to the localhost server will use the samplekey key, which must also be defined in the server’s configuration file with the same name and secret. The key statement indicates that samplekey uses the HMAC-SHA256 algorithm and its secret clause contains the base-64 encoding of the HMAC-SHA256 secret enclosed in double quotes.

If rndc -s testserver is used then rndc will connect to server on localhost port 5353 using the key testkey.

To generate a random secret with rndc-confgen:

rndc-confgen

A complete rndc.conf file, including the randomly generated key, will be written to the standard output. Commented-out key and controls statements for named.conf are also printed.

To generate a base-64 secret with mmencode:

echo "known plaintext for a secret" | mmencode

Name Server Configuration¶

The name server must be configured to accept rndc connections and to recognize the key specified in the rndc.conf file, using the controls statement in named.conf. See the sections on the controls statement in the BIND 9 Administrator Reference Manual for details.

rndc - name server control utility¶

Synopsis¶

rndc [-b source-address] [-c config-file] [-k key-file] [-s server] [-p port] [-q] [-r] [-V] [-y key_id] [[-4] | [-6]] {command}

Description¶

rndc controls the operation of a name server. It supersedes the ndc utility that was provided in old BIND releases. If rndc is invoked with no command line options or arguments, it prints a short summary of the supported commands and the available options and their arguments.

rndc communicates with the name server over a TCP connection, sending commands authenticated with digital signatures. In the current versions of rndc and named, the only supported authentication algorithms are HMAC-MD5 (for compatibility), HMAC-SHA1, HMAC-SHA224, HMAC-SHA256 (default), HMAC-SHA384 and HMAC-SHA512. They use a shared secret on each end of the connection. This provides TSIG-style authentication for the command request and the name server’s response. All commands sent over the channel must be signed by a key_id known to the server.

rndc reads a configuration file to determine how to contact the name server and decide what algorithm and key it should use.

Options¶

-4: Use IPv4 only.
-6: Use IPv6 only.
-b source-address: Use source-address as the source address for the connection to the server. Multiple instances are permitted to allow setting of both the IPv4 and IPv6 source addresses.
-c config-file: Use config-file as the configuration file instead of the default, /etc/rndc.conf.
-k key-file: Use key-file as the key file instead of the default, /etc/rndc.key. The key in /etc/rndc.key will be used to authenticate commands sent to the server if the config-file does not exist.
-s server: server is the name or address of the server which matches a server statement in the configuration file for rndc. If no server is supplied on the command line, the host named by the default-server clause in the options statement of the rndc configuration file will be used.
-p port: Send commands to TCP port port instead of BIND 9’s default control channel port, 953.
-q: Quiet mode: Message text returned by the server will not be printed except when there is an error.
-r: Instructs rndc to print the result code returned by named after executing the requested command (e.g., ISC_R_SUCCESS, ISC_R_FAILURE, etc).
-V: Enable verbose logging.
-y key_id: Use the key key_id from the configuration file. key_id must be known by named with the same algorithm and secret string in order for control message validation to succeed. If no key_id is specified, rndc will first look for a key clause in the server statement of the server being used, or if no server statement is present for that host, then the default-key clause of the options statement. Note that the configuration file contains shared secrets which are used to send authenticated control commands to name servers. It should therefore not have general read or write access.

Commands¶

A list of commands supported by rndc can be seen by running rndc without arguments.

Currently supported commands are:

addzone zone [class [view]] configuration

Add a zone while the server is running. This command requires the allow-new-zones option to be set to yes. The configuration string specified on the command line is the zone configuration text that would ordinarily be placed in named.conf(5).

The configuration is saved in a file called viewname.nzf (or, if named(8) is compiled with liblmdb, an LMDB database file called viewname.nzd). viewname is the name of the view, unless the view name contains characters that are incompatible with use as a file name, in which case a cryptographic hash of the view name is used instead. When named(8) is restarted, the file will be loaded into the view configuration, so that zones that were added can persist after a restart.

This sample addzone command would add the zone example.com to the default view:

$rndc addzone example.com '{ type master; file "example.com.db"; };'

(Note the brackets and semi-colon around the zone configuration text.)

See also rndc delzone and rndc modzone.

delzone [-clean] zone [class [view]]

Delete a zone while the server is running.

If the -clean argument is specified, the zone’s master file (and journal file, if any) will be deleted along with the zone. Without the -clean option, zone files must be cleaned up by hand. (If the zone is of type “slave” or “stub”, the files needing to be cleaned up will be reported in the output of the rndc delzone command.)

If the zone was originally added via rndc addzone, then it will be removed permanently. However, if it was originally configured in named.conf, then that original configuration is still in place; when the server is restarted or reconfigured, the zone will come back. To remove it permanently, it must also be removed from named.conf

See also rndc addzone and rndc modzone.

dnssec [-status zone [class [view]]

Show the DNSSEC signing state for the specified zone. Requires the zone to have a “dnssec-policy”.

dnstap ( -reopen | -roll [number] )

Close and re-open DNSTAP output files. rndc dnstap -reopen allows the output file to be renamed externally, so that named(8) can truncate and re-open it. rndc dnstap -roll causes the output file to be rolled automatically, similar to log files; the most recent output file has “.0” appended to its name; the previous most recent output file is moved to “.1”, and so on. If number is specified, then the number of backup log files is limited to that number.

Dump the server’s caches (default) and/or zones to the dump file for the specified views. If no view is specified, all views are dumped. (See the dump-file option in the BIND 9 Administrator Reference Manual.)

flush

Flushes the server’s cache.

flushname name [view]

Flushes the given name from the view’s DNS cache and, if applicable, from the view’s nameserver address database, bad server cache and SERVFAIL cache.

flushtree name [view]

Flushes the given name, and all of its subdomains, from the view’s DNS cache, address database, bad server cache, and SERVFAIL cache.

freeze [zone [class [view]]]

Suspend updates to a dynamic zone. If no zone is specified, then all zones are suspended. This allows manual edits to be made to a zone normally updated by dynamic update. It also causes changes in the journal file to be synced into the master file. All dynamic update attempts will be refused while the zone is frozen.

Limitations¶

There is currently no way to provide the shared secret for a key_id without using the configuration file.

Several error messages could be clearer.

nsec3hash - generate NSEC3 hash¶

Synopsis¶

nsec3hash {salt} {algorithm} {iterations} {domain}

nsec3hash -r {algorithm} {flags} {iterations} {salt} {domain}

Description¶

nsec3hash generates an NSEC3 hash based on a set of NSEC3 parameters. This can be used to check the validity of NSEC3 records in a signed zone.

If this command is invoked as nsec3hash -r, it takes arguments in an order matching the first four fields of an NSEC3 record, followed by the domain name: algorithm, flags, iterations, salt, domain. This makes it convenient to copy and paste a portion of an NSEC3 or NSEC3PARAM record into a command line to confirm the correctness of an NSEC3 hash.

Arguments¶

salt: The salt provided to the hash algorithm.
algorithm: A number indicating the hash algorithm. Currently the only supported hash algorithm for NSEC3 is SHA-1, which is indicated by the number 1; consequently “1” is the only useful value for this argument.
flags: Provided for compatibility with NSEC3 record presentation format, but ignored since the flags do not affect the hash.
iterations: The number of additional times the hash should be performed.
domain: The domain name to be hashed.

dnstap-read - print dnstap data in human-readable form¶

Synopsis¶

dnstap-read [-m] [-p] [-x] [-y] {file}

Description¶

dnstap-read reads dnstap data from a specified file and prints it in a human-readable format. By default, dnstap data is printed in a short summary format, but if the -y option is specified, then a longer and more detailed YAML format is used instead.

Options¶

-m: Trace memory allocations; used for debugging memory leaks.
-p: After printing the dnstap data, print the text form of the DNS message that was encapsulated in the dnstap frame.
-x: After printing the dnstap data, print a hex dump of the wire form of the DNS message that was encapsulated in the dnstap frame.
-y: Print dnstap data in a detailed YAML format.

named-nzd2nzf - convert an NZD database to NZF text format¶

Synopsis¶

named-nzd2nzf {filename}

Description¶

named-nzd2nzf converts an NZD database to NZF format and prints it to standard output. This can be used to review the configuration of zones that were added to named via rndc addzone. It can also be used to restore the old file format when rolling back from a newer version of BIND to an older version.

Arguments¶

filename: The name of the .nzd file whose contents should be printed.

named-journalprint - print zone journal in human-readable form¶

Synopsis¶

named-journalprint {journal}

Description¶

named-journalprint prints the contents of a zone journal file in a human-readable form.

Journal files are automatically created by named when changes are made to dynamic zones (e.g., by nsupdate). They record each addition or deletion of a resource record, in binary format, allowing the changes to be re-applied to the zone when the server is restarted after a shutdown or crash. By default, the name of the journal file is formed by appending the extension .jnl to the name of the corresponding zone file.

named-journalprint converts the contents of a given journal file into a human-readable text format. Each line begins with “add” or “del”, to indicate whether the record was added or deleted, and continues with the resource record in master-file format.

mdig - DNS pipelined lookup utility¶

Synopsis¶

mdig {@server} [-f filename] [-h] [-v] [ [-4] | [-6] ] [-m] [-b address] [-p port#] [-c class] [-t type] [-i] [-x addr] [plusopt…]

mdig {-h}

mdig [@server] {global-opt…} { {local-opt…} {query} …}

Description¶

mdig is a multiple/pipelined query version of dig: instead of waiting for a response after sending each query, it begins by sending all queries. Responses are displayed in the order in which they are received, not in the order the corresponding queries were sent.

mdig options are a subset of the dig options, and are divided into “anywhere options” which can occur anywhere, “global options” which must occur before the query name (or they are ignored with a warning), and “local options” which apply to the next query on the command line.

The @server option is a mandatory global option. It is the name or IP address of the name server to query. (Unlike dig, this value is not retrieved from /etc/resolv.conf.) It can be an IPv4 address in dotted-decimal notation, an IPv6 address in colon-delimited notation, or a hostname. When the supplied server argument is a hostname, mdig resolves that name before querying the name server.

mdig provides a number of query options which affect the way in which lookups are made and the results displayed. Some of these set or reset flag bits in the query header, some determine which sections of the answer get printed, and others determine the timeout and retry strategies.

Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option. These may be preceded by the string no to negate the meaning of that keyword. Other keywords assign values to options like the timeout interval. They have the form +keyword=value.

Anywhere Options¶

The -f option makes mdig operate in batch mode by reading a list of lookup requests to process from the file filename. The file contains a number of queries, one per line. Each entry in the file should be organized in the same way they would be presented as queries to mdig using the command-line interface.

The -h causes mdig to print the detailed help with the full list of options and exit.

The -v causes mdig to print the version number and exit.

Global Options¶

The -4 option forces mdig to only use IPv4 query transport.

The -6 option forces mdig to only use IPv6 query transport.

The -b option sets the source IP address of the query to address. This must be a valid address on one of the host’s network interfaces or “0.0.0.0” or “::”. An optional port may be specified by appending “#<port>”

The -m option enables memory usage debugging.

The -p option is used when a non-standard port number is to be queried. port# is the port number that mdig will send its queries instead of the standard DNS port number 53. This option would be used to test a name server that has been configured to listen for queries on a non-standard port number.

The global query options are:

+[no]additional: Display [do not display] the additional section of a reply. The default is to display it.
+[no]all: Set or clear all display flags.
+[no]answer: Display [do not display] the answer section of a reply. The default is to display it.
+[no]authority: Display [do not display] the authority section of a reply. The default is to display it.
+[no]besteffort: Attempt to display the contents of messages which are malformed. The default is to not display malformed answers.
+[no]cl: Display [do not display] the CLASS when printing the record.
+[no]comments: Toggle the display of comment lines in the output. The default is to print comments.
+[no]continue: Continue on errors (e.g. timeouts).
+[no]crypto: Toggle the display of cryptographic fields in DNSSEC records. The contents of these field are unnecessary to debug most DNSSEC validation failures and removing them makes it easier to see the common failures. The default is to display the fields. When omitted they are replaced by the string “[omitted]” or in the DNSKEY case the key id is displayed as the replacement, e.g. “[ key id = value ]”.
+dscp[=value]: Set the DSCP code point to be used when sending the query. Valid DSCP code points are in the range [0..63]. By default no code point is explicitly set.
+[no]multiline: Print records like the SOA records in a verbose multi-line format with human-readable comments. The default is to print each record on a single line, to facilitate machine parsing of the mdig output.
+[no]question: Print [do not print] the question section of a query when an answer is returned. The default is to print the question section as a comment.
+[no]rrcomments: Toggle the display of per-record comments in the output (for example, human-readable key information about DNSKEY records). The default is not to print record comments unless multiline mode is active.
+[no]short: Provide a terse answer. The default is to print the answer in a verbose form.
+split=W: Split long hex- or base64-formatted fields in resource records into chunks of W characters (where W is rounded up to the nearest multiple of 4). +nosplit or +split=0 causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active.
+[no]tcp: Use [do not use] TCP when querying name servers. The default behavior is to use UDP.
+[no]ttlid: Display [do not display] the TTL when printing the record.
+[no]ttlunits: Display [do not display] the TTL in friendly human-readable time units of “s”, “m”, “h”, “d”, and “w”, representing seconds, minutes, hours, days and weeks. Implies +ttlid.
+[no]vc: Use [do not use] TCP when querying name servers. This alternate syntax to +[no]tcp is provided for backwards compatibility. The “vc” stands for “virtual circuit”.

Local Options¶

The -c option sets the query class to class. It can be any valid query class which is supported in BIND 9. The default query class is “IN”.

The -t option sets the query type to type. It can be any valid query type which is supported in BIND 9. The default query type is “A”, unless the -x option is supplied to indicate a reverse lookup with the “PTR” query type.

Reverse lookups MDASH mapping addresses to names MDASH are simplified by the -x option. addr is an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. mdig automatically performs a lookup for a query name like 11.12.13.10.in-addr.arpa and sets the query type and class to PTR and IN respectively. By default, IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.

The local query options are:

+[no]aaflag

A synonym for +[no]aaonly.

+[no]aaonly

Sets the “aa” flag in the query.

+[no]adflag

Set [do not set] the AD (authentic data) bit in the query. This requests the server to return whether all of the answer and authority sections have all been validated as secure according to the security policy of the server. AD=1 indicates that all records have been validated as secure and the answer is not from a OPT-OUT range. AD=0 indicate that some part of the answer was insecure or not validated. This bit is set by default.

+bufsize=B

Set the UDP message buffer size advertised using EDNS0 to B bytes. The maximum and minimum sizes of this buffer are 65535 and 0 respectively. Values outside this range are rounded up or down appropriately. Values other than zero will cause a EDNS query to be sent.

+[no]cdflag

Set [do not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC validation of responses.

+[no]cookie=####

Send a COOKIE EDNS option, with optional value. Replaying a COOKIE from a previous response will allow the server to identify a previous client. The default is +nocookie.

+[no]dnssec

Requests DNSSEC records be sent by setting the DNSSEC OK bit (DO) in the OPT record in the additional section of the query.

+[no]edns[=#]

Specify the EDNS version to query with. Valid values are 0 to 255. Setting the EDNS version will cause a EDNS query to be sent. +noedns clears the remembered EDNS version. EDNS is set to 0 by default.

+[no]ednsflags[=#]

Set the must-be-zero EDNS flags bits (Z bits) to the specified value. Decimal, hex and octal encodings are accepted. Setting a named flag (e.g. DO) will silently be ignored. By default, no Z bits are set.

+[no]ednsopt[=code[:value]]

Specify EDNS option with code point code and optionally payload of value as a hexadecimal string. +noednsopt clears the EDNS options to be sent.

+[no]expire

Send an EDNS Expire option.

+[no]nsid

Include an EDNS name server ID request when sending a query.

+[no]recurse

Toggle the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means mdig normally sends recursive queries.

+retry=T

Sets the number of times to retry UDP queries to server to T instead of the default, 2. Unlike +tries, this does not include the initial query.

+[no]subnet=addr[/prefix-length]

Send (don’t send) an EDNS Client Subnet option with the specified IP address or network prefix.

mdig +subnet=0.0.0.0/0, or simply mdig +subnet=0 for short, sends an EDNS client-subnet option with an empty address and a source prefix-length of zero, which signals a resolver that the client’s address information must not be used when resolving this query.

+timeout=T

Sets the timeout for a query to T seconds. The default timeout is 5 seconds for UDP transport and 10 for TCP. An attempt to set T to less than 1 will result in a query timeout of 1 second being applied.

+tries=T

Sets the number of times to try UDP queries to server to T instead of the default, 3. If T is less than or equal to zero, the number of tries is silently rounded up to 1.

+udptimeout=T

Sets the timeout between UDP query retries.

+[no]unknownformat

Print all RDATA in unknown RR type presentation format (RFC 3597). The default is to print RDATA for known types in the type’s presentation format.

+[no]yaml

Print the responses in a detailed YAML format.

+[no]zflag

Set [do not set] the last unassigned DNS header flag in a DNS query. This flag is off by default.

named-rrchecker - syntax checker for individual DNS resource records¶

Synopsis¶

named-rrchecker [-h] [-o origin] [-p] [-u] [-C] [-T] [-P]

Description¶

named-rrchecker read a individual DNS resource record from standard input and checks if it is syntactically correct.

The -h prints out the help menu.

The -o origin option specifies a origin to be used when interpreting the record.

The -p prints out the resulting record in canonical form. If there is no canonical form defined then the record will be printed in unknown record format.

The -u prints out the resulting record in unknown record form.

The -C, -T and -P print out the known class, standard type and private type mnemonics respectively.

arpaname - translate IP addresses to the corresponding ARPA names¶

Synopsis¶

arpaname {ipaddress …}

Description¶

arpaname translates IP addresses (IPv4 and IPv6) to the corresponding IN-ADDR.ARPA or IP6.ARPA names.

dnssec-revoke - set the REVOKED bit on a DNSSEC key¶

Synopsis¶

dnssec-revoke [-hr] [-v level] [-V] [-K directory] [-E engine] [-f] [-R] {keyfile}

Description¶

dnssec-revoke reads a DNSSEC key file, sets the REVOKED bit on the key as defined in RFC 5011, and creates a new pair of key files containing the now-revoked key.

Options¶

-h

Emit usage message and exit.

-K directory

Sets the directory in which the key files are to reside.

-r

After writing the new keyset files remove the original keyset files.

-v level

Sets the debugging level.

-V

Prints version information.

-E engine

Specifies the cryptographic hardware to use, when applicable.

When BIND is built with OpenSSL PKCS#11 support, this defaults to the string “pkcs11”, which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (–enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via “–with-pkcs11”.

-f

Force overwrite: Causes dnssec-revoke to write the new key pair even if a file already exists matching the algorithm and key ID of the revoked key.

-R

Print the key tag of the key with the REVOKE bit set but do not revoke the key.

dnssec-cds - change DS records for a child zone based on CDS/CDNSKEY¶

Synopsis¶

dnssec-cds [-a alg…] [-c class] [-D] {-d dsset-file} {-f child-file} [-i [extension]] [-s start-time] [-T ttl] [-u] [-v level] [-V] {domain}

Description¶

The dnssec-cds command changes DS records at a delegation point based on CDS or CDNSKEY records published in the child zone. If both CDS and CDNSKEY records are present in the child zone, the CDS is preferred. This enables a child zone to inform its parent of upcoming changes to its key-signing keys; by polling periodically with dnssec-cds, the parent can keep the DS records up to date and enable automatic rolling of KSKs.

Two input files are required. The -f child-file option specifies a file containing the child’s CDS and/or CDNSKEY records, plus RRSIG and DNSKEY records so that they can be authenticated. The -d path option specifies the location of a file containing the current DS records. For example, this could be a dsset- file generated by dnssec-signzone, or the output of dnssec-dsfromkey, or the output of a previous run of dnssec-cds.

The dnssec-cds command uses special DNSSEC validation logic specified by RFC 7344. It requires that the CDS and/or CDNSKEY records are validly signed by a key represented in the existing DS records. This will typically be the pre-existing key-signing key (KSK).

For protection against replay attacks, the signatures on the child records must not be older than they were on a previous run of dnssec-cds. This time is obtained from the modification time of the dsset- file, or from the -s option.

To protect against breaking the delegation, dnssec-cds ensures that the DNSKEY RRset can be verified by every key algorithm in the new DS RRset, and that the same set of keys are covered by every DS digest type.

By default, replacement DS records are written to the standard output; with the -i option the input file is overwritten in place. The replacement DS records will be the same as the existing records when no change is required. The output can be empty if the CDS / CDNSKEY records specify that the child zone wants to go insecure.

Warning: Be careful not to delete the DS records when dnssec-cds fails!

Alternatively, dnssec-cds -u writes an nsupdate script to the standard output. You can use the -u and -i options together to maintain a dsset- file as well as emit an nsupdate script.

Options¶

-a algorithm

Specify a digest algorithm to use when converting CDNSKEY records to DS records. This option can be repeated, so that multiple DS records are created for each CDNSKEY record. This option has no effect when using CDS records.

The algorithm must be one of SHA-1, SHA-256, or SHA-384. These values are case insensitive, and the hyphen may be omitted. If no algorithm is specified, the default is SHA-256.

-c class

Specifies the DNS class of the zones.

-D

Generate DS records from CDNSKEY records if both CDS and CDNSKEY records are present in the child zone. By default CDS records are preferred.

-d path

Location of the parent DS records. The path can be the name of a file containing the DS records, or if it is a directory, dnssec-cds looks for a dsset- file for the domain inside the directory.

To protect against replay attacks, child records are rejected if they were signed earlier than the modification time of the dsset- file. This can be adjusted with the -s option.

-f child-file

File containing the child’s CDS and/or CDNSKEY records, plus its DNSKEY records and the covering RRSIG records so that they can be authenticated.

The EXAMPLES below describe how to generate this file.

-iextension

Update the dsset- file in place, instead of writing DS records to the standard output.

There must be no space between the -i and the extension. If you provide no extension then the old dsset- is discarded. If an extension is present, a backup of the old dsset- file is kept with the extension appended to its filename.

To protect against replay attacks, the modification time of the dsset- file is set to match the signature inception time of the child records, provided that is later than the file’s current modification time.

-s start-time

Specify the date and time after which RRSIG records become acceptable. This can be either an absolute or relative time. An absolute start time is indicated by a number in YYYYMMDDHHMMSS notation; 20170827133700 denotes 13:37:00 UTC on August 27th, 2017. A time relative to the dsset- file is indicated with -N, which is N seconds before the file modification time. A time relative to the current time is indicated with now+N.

If no start-time is specified, the modification time of the dsset- file is used.

-T ttl

Specifies a TTL to be used for new DS records. If not specified, the default is the TTL of the old DS records. If they had no explicit TTL then the new DS records also have no explicit TTL.

-u

Write an nsupdate script to the standard output, instead of printing the new DS reords. The output will be empty if no change is needed.

Note: The TTL of new records needs to be specified, either in the original dsset- file, or with the -T option, or using the nsupdate ttl command.

-V

Print version information.

-v level

Sets the debugging level. Level 1 is intended to be usefully verbose for general users; higher levels are intended for developers.

domain

The name of the delegation point / child zone apex.

Exit Status¶

The dnssec-cds command exits 0 on success, or non-zero if an error occurred.

In the success case, the DS records might or might not need to be changed.

Examples¶

Before running dnssec-signzone, you can ensure that the delegations are up-to-date by running dnssec-cds on every dsset- file.

To fetch the child records required by dnssec-cds you can invoke dig as in the script below. It’s okay if the dig fails since dnssec-cds performs all the necessary checking.

for f in dsset-*
do
    d=${f#dsset-}
    dig +dnssec +noall +answer $d DNSKEY $d CDNSKEY $d CDS |
    dnssec-cds -i -f /dev/stdin -d $f $d
done

When the parent zone is automatically signed by named, you can use dnssec-cds with nsupdate to maintain a delegation as follows. The dsset- file allows the script to avoid having to fetch and validate the parent DS records, and it keeps the replay attack protection time.

dig +dnssec +noall +answer $d DNSKEY $d CDNSKEY $d CDS |
dnssec-cds -u -i -f /dev/stdin -d $f $d |
nsupdate -l

dnssec-keygen: DNSSEC key generation tool¶

Synopsis¶

dnssec-keygen [-3] [-A date/offset] [-a algorithm] [-b keysize] [-C] [-c class] [-D date/offset] [-d bits] [-D sync date/offset] [-E engine] [-f flag] [-G] [-g generator] [-h] [-I date/offset] [-i interval] [-K directory] [-k policy] [-L ttl] [-l file] [-n nametype] [-P date/offset] [-P sync date/offset] [-p protocol] [-q] [-R date/offset] [-S key] [-s strength] [-T rrtype] [-t type] [-V] [-v level] {name}

Description¶

dnssec-keygen generates keys for DNSSEC (Secure DNS), as defined in RFC 2535 and RFC 4034. It can also generate keys for use with TSIG (Transaction Signatures) as defined in RFC 2845, or TKEY (Transaction Key) as defined in RFC 2930.

The name of the key is specified on the command line. For DNSSEC keys, this must match the name of the zone for which the key is being generated.

The dnssec-keymgr command acts as a wrapper around dnssec-keygen, generating and updating keys as needed to enforce defined security policies such as key rollover scheduling. Using dnssec-keymgr may be preferable to direct use of dnssec-keygen.

Options¶

-3

Use an NSEC3-capable algorithm to generate a DNSSEC key. If this option is used with an algorithm that has both NSEC and NSEC3 versions, then the NSEC3 version will be used; for example, dnssec-keygen -3a RSASHA1 specifies the NSEC3RSASHA1 algorithm.

-a algorithm

Selects the cryptographic algorithm. For DNSSEC keys, the value of algorithm must be one of RSASHA1, NSEC3RSASHA1, RSASHA256, RSASHA512, ECDSAP256SHA256, ECDSAP384SHA384, ED25519 or ED448. For TKEY, the value must be DH (Diffie Hellman); specifying his value will automatically set the -T KEY option as well.

These values are case insensitive. In some cases, abbreviations are supported, such as ECDSA256 for ECDSAP256SHA256 and ECDSA384 for ECDSAP384SHA384. If RSASHA1 is specified along with the -3 option, then NSEC3RSASHA1 will be used instead.

This parameter must be specified except when using the -S option, which copies the algorithm from the predecessor key.

In prior releases, HMAC algorithms could be generated for use as TSIG keys, but that feature has been removed as of BIND 9.13.0. Use tsig-keygen to generate TSIG keys.

-b keysize

Specifies the number of bits in the key. The choice of key size depends on the algorithm used. RSA keys must be between 1024 and 4096 bits. Diffie Hellman keys must be between 128 and 4096 bits. Elliptic curve algorithms don’t need this parameter.

If the key size is not specified, some algorithms have pre-defined defaults. For example, RSA keys for use as DNSSEC zone signing keys have a default size of 1024 bits; RSA keys for use as key signing keys (KSKs, generated with -f KSK) default to 2048 bits.

-C

Compatibility mode: generates an old-style key, without any timing metadata. By default, dnssec-keygen will include the key’s creation date in the metadata stored with the private key, and other dates may be set there as well (publication date, activation date, etc). Keys that include this data may be incompatible with older versions of BIND; the -C option suppresses them.

-c class

Indicates that the DNS record containing the key should have the specified class. If not specified, class IN is used.

-d bits

Key size in bits. For the algorithms RSASHA1, NSEC3RSASA1, RSASHA256 and RSASHA512 the key size must be in range 1024-4096. DH size is between 128 and 4096. This option is ignored for algorithms ECDSAP256SHA256, ECDSAP384SHA384, ED25519 and ED448.

-E engine

Specifies the cryptographic hardware to use, when applicable.

When BIND is built with OpenSSL PKCS#11 support, this defaults to the string “pkcs11”, which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (–enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via “–with-pkcs11”.

-f flag

Set the specified flag in the flag field of the KEY/DNSKEY record. The only recognized flags are KSK (Key Signing Key) and REVOKE.

-G

Generate a key, but do not publish it or sign with it. This option is incompatible with -P and -A.

-g generator

If generating a Diffie Hellman key, use this generator. Allowed values are 2 and 5. If no generator is specified, a known prime from RFC 2539 will be used if possible; otherwise the default is 2.

-h

Prints a short summary of the options and arguments to dnssec-keygen.

-K directory

Sets the directory in which the key files are to be written.

-k policy

Create keys for a specific dnssec-policy. If a policy uses multiple keys, dnssec-keygen will generate multiple keys. This will also create a “.state” file to keep track of the key state.

This option creates keys according to the dnssec-policy configuration, hence it cannot be used together with many of the other options that dnssec-keygen provides.

-L ttl

Sets the default TTL to use for this key when it is converted into a DNSKEY RR. If the key is imported into a zone, this is the TTL that will be used for it, unless there was already a DNSKEY RRset in place, in which case the existing TTL would take precedence. If this value is not set and there is no existing DNSKEY RRset, the TTL will default to the SOA TTL. Setting the default TTL to 0 or none is the same as leaving it unset.

-l file

Provide a configuration file that contains a dnssec-policy statement (matching the policy set with -k).

-n nametype

Specifies the owner type of the key. The value of nametype must either be ZONE (for a DNSSEC zone key (KEY/DNSKEY)), HOST or ENTITY (for a key associated with a host (KEY)), USER (for a key associated with a user(KEY)) or OTHER (DNSKEY). These values are case insensitive. Defaults to ZONE for DNSKEY generation.

-p protocol

Sets the protocol value for the generated key, for use with -T KEY. The protocol is a number between 0 and 255. The default is 3 (DNSSEC). Other possible values for this argument are listed in RFC 2535 and its successors.

-q

Quiet mode: Suppresses unnecessary output, including progress indication. Without this option, when dnssec-keygen is run interactively to generate an RSA or DSA key pair, it will print a string of symbols to stderr indicating the progress of the key generation. A ‘.’ indicates that a random number has been found which passed an initial sieve test; ‘+’ means a number has passed a single round of the Miller-Rabin primality test; a space means that the number has passed all the tests and is a satisfactory key.

-S key

Create a new key which is an explicit successor to an existing key. The name, algorithm, size, and type of the key will be set to match the existing key. The activation date of the new key will be set to the inactivation date of the existing one. The publication date will be set to the activation date minus the prepublication interval, which defaults to 30 days.

-s strength

Specifies the strength value of the key. The strength is a number between 0 and 15, and currently has no defined purpose in DNSSEC.

-T rrtype

Specifies the resource record type to use for the key. rrtype must be either DNSKEY or KEY. The default is DNSKEY when using a DNSSEC algorithm, but it can be overridden to KEY for use with SIG(0).

-t type

Indicates the use of the key, for use with -T KEY. type must be one of AUTHCONF, NOAUTHCONF, NOAUTH, or NOCONF. The default is AUTHCONF. AUTH refers to the ability to authenticate data, and CONF the ability to encrypt data.

-V

Prints version information.

-v level

Sets the debugging level.

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a ‘+’ or ‘-‘, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes ‘y’, ‘mo’, ‘w’, ‘d’, ‘h’, or ‘mi’, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To explicitly prevent a date from being set, use ‘none’ or ‘never’.

-P date/offset

Sets the date on which a key is to be published to the zone. After that date, the key will be included in the zone but will not be used to sign it. If not set, and if the -G option has not been used, the default is “now”.

-P sync date/offset

Sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.

-A date/offset

Sets the date on which the key is to be activated. After that date, the key will be included in the zone and used to sign it. If not set, and if the -G option has not been used, the default is “now”. If set, if and -P is not set, then the publication date will be set to the activation date minus the prepublication interval.

-R date/offset

Sets the date on which the key is to be revoked. After that date, the key will be flagged as revoked. It will be included in the zone and will be used to sign it.

-I date/offset

Sets the date on which the key is to be retired. After that date, the key will still be included in the zone, but it will not be used to sign it.

-D date/offset

Sets the date on which the key is to be deleted. After that date, the key will no longer be included in the zone. (It may remain in the key repository, however.)

-D sync date/offset

Sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.

-i interval

Sets the prepublication interval for a key. If set, then the publication and activation dates must be separated by at least this much time. If the activation date is specified but the publication date isn’t, then the publication date will default to this much time before the activation date; conversely, if the publication date is specified but activation date isn’t, then activation will be set to this much time after publication.

If the key is being created as an explicit successor to another key, then the default prepublication interval is 30 days; otherwise it is zero.

As with date offsets, if the argument is followed by one of the suffixes ‘y’, ‘mo’, ‘w’, ‘d’, ‘h’, or ‘mi’, then the interval is measured in years, months, weeks, days, hours, or minutes, respectively. Without a suffix, the interval is measured in seconds.

Generated Keys¶

When dnssec-keygen completes successfully, it prints a string of the form Knnnn.+aaa+iiiii to the standard output. This is an identification string for the key it has generated.

nnnn is the key name.
aaa is the numeric representation of the algorithm.
iiiii is the key identifier (or footprint).

dnssec-keygen creates two files, with names based on the printed string. Knnnn.+aaa+iiiii.key contains the public key, and Knnnn.+aaa+iiiii.private contains the private key.

The .key file contains a DNSKEY or KEY record. When a zone is being signed by named or dnssec-signzone -S, DNSKEY records are included automatically. In other cases, the .key file can be inserted into a zone file manually or with a $INCLUDE statement.

The .private file contains algorithm-specific fields. For obvious security reasons, this file does not have general read permission.

Example¶

To generate an ECDSAP256SHA256 zone-signing key for the zone example.com, issue the command:

dnssec-keygen -a ECDSAP256SHA256 example.com

The command would print a string of the form:

Kexample.com.+013+26160

In this example, dnssec-keygen creates the files Kexample.com.+013+26160.key and Kexample.com.+013+26160.private.

To generate a matching key-signing key, issue the command:

dnssec-keygen -a ECDSAP256SHA256 -f KSK example.com

dnssec-keyfromlabel - DNSSEC key generation tool¶

Synopsis¶

dnssec-keyfromlabel {-l label} [-3] [-a algorithm] [-A date/offset] [-c class] [-D date/offset] [-D sync date/offset] [-E engine] [-f flag] [-G] [-I date/offset] [-i interval] [-k] [-K directory] [-L ttl] [-n nametype] [-P date/offset] [-P sync date/offset] [-p protocol] [-R date/offset] [-S key] [-t type] [-v level] [-V] [-y] {name}

Description¶

dnssec-keyfromlabel generates a key pair of files that referencing a key object stored in a cryptographic hardware service module (HSM). The private key file can be used for DNSSEC signing of zone data as if it were a conventional signing key created by dnssec-keygen, but the key material is stored within the HSM, and the actual signing takes place there.

The name of the key is specified on the command line. This must match the name of the zone for which the key is being generated.

Options¶

-a algorithm

Selects the cryptographic algorithm. The value of algorithm must be one of RSASHA1, NSEC3RSASHA1, RSASHA256, RSASHA512, ECDSAP256SHA256, ECDSAP384SHA384, ED25519 or ED448.

If no algorithm is specified, then RSASHA1 will be used by default, unless the -3 option is specified, in which case NSEC3RSASHA1 will be used instead. (If -3 is used and an algorithm is specified, that algorithm will be checked for compatibility with NSEC3.)

These values are case insensitive. In some cases, abbreviations are supported, such as ECDSA256 for ECDSAP256SHA256 and ECDSA384 for ECDSAP384SHA384. If RSASHA1 is specified along with the -3 option, then NSEC3RSASHA1 will be used instead.

As of BIND 9.12.0, this option is mandatory except when using the -S option (which copies the algorithm from the predecessory key). Previously, the default for newly generated keys was RSASHA1.

-3

Use an NSEC3-capable algorithm to generate a DNSSEC key. If this option is used with an algorithm that has both NSEC and NSEC3 versions, then the NSEC3 version will be used; for example, dnssec-keygen -3a RSASHA1 specifies the NSEC3RSASHA1 algorithm.

-E engine

Specifies the cryptographic hardware to use.

When BIND is built with OpenSSL PKCS#11 support, this defaults to the string “pkcs11”, which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (–enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via “–with-pkcs11”.

-l label

Specifies the label for a key pair in the crypto hardware.

When BIND 9 is built with OpenSSL-based PKCS#11 support, the label is an arbitrary string that identifies a particular key. It may be preceded by an optional OpenSSL engine name, followed by a colon, as in “pkcs11:keylabel”.

When BIND 9 is built with native PKCS#11 support, the label is a PKCS#11 URI string in the format “pkcs11:keyword=value[;keyword=value;…]” Keywords include “token”, which identifies the HSM; “object”, which identifies the key; and “pin-source”, which identifies a file from which the HSM’s PIN code can be obtained. The label will be stored in the on-disk “private” file.

If the label contains a pin-source field, tools using the generated key files will be able to use the HSM for signing and other operations without any need for an operator to manually enter a PIN. Note: Making the HSM’s PIN accessible in this manner may reduce the security advantage of using an HSM; be sure this is what you want to do before making use of this feature.

-n nametype

Specifies the owner type of the key. The value of nametype must either be ZONE (for a DNSSEC zone key (KEY/DNSKEY)), HOST or ENTITY (for a key associated with a host (KEY)), USER (for a key associated with a user(KEY)) or OTHER (DNSKEY). These values are case insensitive.

-C

Compatibility mode: generates an old-style key, without any metadata. By default, dnssec-keyfromlabel will include the key’s creation date in the metadata stored with the private key, and other dates may be set there as well (publication date, activation date, etc). Keys that include this data may be incompatible with older versions of BIND; the -C option suppresses them.

-c class

Indicates that the DNS record containing the key should have the specified class. If not specified, class IN is used.

-f flag

Set the specified flag in the flag field of the KEY/DNSKEY record. The only recognized flags are KSK (Key Signing Key) and REVOKE.

-G

Generate a key, but do not publish it or sign with it. This option is incompatible with -P and -A.

-h

Prints a short summary of the options and arguments to dnssec-keyfromlabel.

-K directory

Sets the directory in which the key files are to be written.

-k

Generate KEY records rather than DNSKEY records.

-L ttl

Sets the default TTL to use for this key when it is converted into a DNSKEY RR. If the key is imported into a zone, this is the TTL that will be used for it, unless there was already a DNSKEY RRset in place, in which case the existing TTL would take precedence. Setting the default TTL to 0 or none removes it.

-p protocol

Sets the protocol value for the key. The protocol is a number between 0 and 255. The default is 3 (DNSSEC). Other possible values for this argument are listed in RFC 2535 and its successors.

-S key

Generate a key as an explicit successor to an existing key. The name, algorithm, size, and type of the key will be set to match the predecessor. The activation date of the new key will be set to the inactivation date of the existing one. The publication date will be set to the activation date minus the prepublication interval, which defaults to 30 days.

-t type

Indicates the use of the key. type must be one of AUTHCONF, NOAUTHCONF, NOAUTH, or NOCONF. The default is AUTHCONF. AUTH refers to the ability to authenticate data, and CONF the ability to encrypt data.

-v level

Sets the debugging level.

-V

Prints version information.

-y

Allows DNSSEC key files to be generated even if the key ID would collide with that of an existing key, in the event of either key being revoked. (This is only safe to use if you are sure you won’t be using RFC 5011 trust anchor maintenance with either of the keys involved.)

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a ‘+’ or ‘-‘, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes ‘y’, ‘mo’, ‘w’, ‘d’, ‘h’, or ‘mi’, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To explicitly prevent a date from being set, use ‘none’ or ‘never’.

-P date/offset

Sets the date on which a key is to be published to the zone. After that date, the key will be included in the zone but will not be used to sign it. If not set, and if the -G option has not been used, the default is “now”.

-P sync date/offset

Sets the date on which the CDS and CDNSKEY records which match this key are to be published to the zone.

-A date/offset

Sets the date on which the key is to be activated. After that date, the key will be included in the zone and used to sign it. If not set, and if the -G option has not been used, the default is “now”.

-R date/offset

Sets the date on which the key is to be revoked. After that date, the key will be flagged as revoked. It will be included in the zone and will be used to sign it.

-I date/offset

Sets the date on which the key is to be retired. After that date, the key will still be included in the zone, but it will not be used to sign it.

-D date/offset

Sets the date on which the key is to be deleted. After that date, the key will no longer be included in the zone. (It may remain in the key repository, however.)

-D sync date/offset

Sets the date on which the CDS and CDNSKEY records which match this key are to be deleted.

-i interval

Sets the prepublication interval for a key. If set, then the publication and activation dates must be separated by at least this much time. If the activation date is specified but the publication date isn’t, then the publication date will default to this much time before the activation date; conversely, if the publication date is specified but activation date isn’t, then activation will be set to this much time after publication.

If the key is being created as an explicit successor to another key, then the default prepublication interval is 30 days; otherwise it is zero.

As with date offsets, if the argument is followed by one of the suffixes ‘y’, ‘mo’, ‘w’, ‘d’, ‘h’, or ‘mi’, then the interval is measured in years, months, weeks, days, hours, or minutes, respectively. Without a suffix, the interval is measured in seconds.

Generated Key Files¶

When dnssec-keyfromlabel completes successfully, it prints a string of the form Knnnn.+aaa+iiiii to the standard output. This is an identification string for the key files it has generated.

nnnn is the key name.
aaa is the numeric representation of the algorithm.
iiiii is the key identifier (or footprint).

dnssec-keyfromlabel creates two files, with names based on the printed string. Knnnn.+aaa+iiiii.key contains the public key, and Knnnn.+aaa+iiiii.private contains the private key.

The .key file contains a DNS KEY record that can be inserted into a zone file (directly or with a $INCLUDE statement).

The .private file contains algorithm-specific fields. For obvious security reasons, this file does not have general read permission.

dnssec-verify - DNSSEC zone verification tool¶

Synopsis¶

dnssec-verify [-c class] [-E engine] [-I input-format] [-o origin] [-q] [-v level] [-V] [-x] [-z] {zonefile}

Description¶

dnssec-verify verifies that a zone is fully signed for each algorithm found in the DNSKEY RRset for the zone, and that the NSEC / NSEC3 chains are complete.

Options¶

-c class

Specifies the DNS class of the zone.

-E engine

Specifies the cryptographic hardware to use, when applicable.

When BIND is built with OpenSSL PKCS#11 support, this defaults to the string “pkcs11”, which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (–enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via “–with-pkcs11”.

-I input-format

The format of the input zone file. Possible formats are "text" (default) and "raw". This option is primarily intended to be used for dynamic signed zones so that the dumped zone file in a non-text format containing updates can be verified independently. The use of this option does not make much sense for non-dynamic zones.

-o origin

The zone origin. If not specified, the name of the zone file is assumed to be the origin.

-v level

Sets the debugging level.

-V

Prints version information.

-q

Quiet mode: Suppresses output. Without this option, when dnssec-verify is run it will print to standard output the number of keys in use, the algorithms used to verify the zone was signed correctly and other status information. With it, all non-error output is suppressed, and only the exit code will indicate success.

-x

Only verify that the DNSKEY RRset is signed with key-signing keys. Without this flag, it is assumed that the DNSKEY RRset will be signed by all active keys. When this flag is set, it will not be an error if the DNSKEY RRset is not signed by zone-signing keys. This corresponds to the -x option in dnssec-signzone.

-z

Ignore the KSK flag on the keys when determining whether the zone if correctly signed. Without this flag it is assumed that there will be a non-revoked, self-signed DNSKEY with the KSK flag set for each algorithm and that RRsets other than DNSKEY RRset will be signed with a different DNSKEY without the KSK flag set.

With this flag set, we only require that for each algorithm, there will be at least one non-revoked, self-signed DNSKEY, regardless of the KSK flag state, and that other RRsets will be signed by a non-revoked key for the same algorithm that includes the self-signed key; the same key may be used for both purposes. This corresponds to the -z option in dnssec-signzone.

zonefile

The file containing the zone to be signed.

dnssec-settime: set the key timing metadata for a DNSSEC key¶

Synopsis¶

dnssec-settime [-f] [-K directory] [-L ttl] [-P date/offset] [-P sync date/offset] [-A date/offset] [-R date/offset] [-I date/offset] [-D date/offset] [-D sync date/offset] [-S key] [-i interval] [-h] [-V] [-v level] [-E engine] {keyfile} [-s] [-g state] [-d state date/offset] [-k state date/offset] [-r state date/offset] [-z state date/offset]

Description¶

dnssec-settime reads a DNSSEC private key file and sets the key timing metadata as specified by the -P, -A, -R, -I, and -D options. The metadata can then be used by dnssec-signzone or other signing software to determine when a key is to be published, whether it should be used for signing a zone, etc.

If none of these options is set on the command line, then dnssec-settime simply prints the key timing metadata already stored in the key.

When key metadata fields are changed, both files of a key pair (Knnnn.+aaa+iiiii.key and Knnnn.+aaa+iiiii.private) are regenerated.

Metadata fields are stored in the private file. A human-readable description of the metadata is also placed in comments in the key file. The private file’s permissions are always set to be inaccessible to anyone other than the owner (mode 0600).

When working with state files, it is possible to update the timing metadata in those files as well with -s. If this option is used you can also update key states with -d (DS), -k (DNSKEY), -r (RRSIG of KSK), or -z (RRSIG of ZSK). Allowed states are HIDDEN, RUMOURED, OMNIPRESENT, and UNRETENTIVE.

You can also set the goal state of the key with -g. This should be either HIDDEN or OMNIPRESENT (representing whether the key should be removed from the zone, or published).

It is NOT RECOMMENDED to manipulate state files manually except for testing purposes.

Options¶

-f

Force an update of an old-format key with no metadata fields. Without this option, dnssec-settime will fail when attempting to update a legacy key. With this option, the key will be recreated in the new format, but with the original key data retained. The key’s creation date will be set to the present time. If no other values are specified, then the key’s publication and activation dates will also be set to the present time.

-K directory

Sets the directory in which the key files are to reside.

-L ttl

Sets the default TTL to use for this key when it is converted into a DNSKEY RR. If the key is imported into a zone, this is the TTL that will be used for it, unless there was already a DNSKEY RRset in place, in which case the existing TTL would take precedence. If this value is not set and there is no existing DNSKEY RRset, the TTL will default to the SOA TTL. Setting the default TTL to 0 or none removes it from the key.

-h

Emit usage message and exit.

-V

Prints version information.

-v level

Sets the debugging level.

-E engine

Specifies the cryptographic hardware to use, when applicable.

When BIND is built with OpenSSL PKCS#11 support, this defaults to the string “pkcs11”, which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (–enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via “–with-pkcs11”.

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a ‘+’ or ‘-‘, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes ‘y’, ‘mo’, ‘w’, ‘d’, ‘h’, or ‘mi’, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To unset a date, use ‘none’ or ‘never’.

-P date/offset

Sets the date on which a key is to be published to the zone. After that date, the key will be included in the zone but will not be used to sign it.

-P sync date/offset

Sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.

-A date/offset

Sets the date on which the key is to be activated. After that date, the key will be included in the zone and used to sign it.

-R date/offset

Sets the date on which the key is to be revoked. After that date, the key will be flagged as revoked. It will be included in the zone and will be used to sign it.

-I date/offset

Sets the date on which the key is to be retired. After that date, the key will still be included in the zone, but it will not be used to sign it.

-D date/offset

Sets the date on which the key is to be deleted. After that date, the key will no longer be included in the zone. (It may remain in the key repository, however.)

-D sync date/offset

Sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.

-S predecessor key

Select a key for which the key being modified will be an explicit successor. The name, algorithm, size, and type of the predecessor key must exactly match those of the key being modified. The activation date of the successor key will be set to the inactivation date of the predecessor. The publication date will be set to the activation date minus the prepublication interval, which defaults to 30 days.

-i interval

Sets the prepublication interval for a key. If set, then the publication and activation dates must be separated by at least this much time. If the activation date is specified but the publication date isn’t, then the publication date will default to this much time before the activation date; conversely, if the publication date is specified but activation date isn’t, then activation will be set to this much time after publication.

If the key is being set to be an explicit successor to another key, then the default prepublication interval is 30 days; otherwise it is zero.

As with date offsets, if the argument is followed by one of the suffixes ‘y’, ‘mo’, ‘w’, ‘d’, ‘h’, or ‘mi’, then the interval is measured in years, months, weeks, days, hours, or minutes, respectively. Without a suffix, the interval is measured in seconds.

Key State Options¶

Known key states are HIDDEN, RUMOURED, OMNIPRESENT and UNRETENTIVE. These should not be set manually except for testing purposes.

-s: When setting key timing data, also update the state file.
-g: Set the goal state for this key. Must be HIDDEN or OMNIPRESENT.
-d: Set the DS state for this key, and when it was last changed.
-k: Set the DNSKEY state for this key, and when it was last changed.
-r: Set the RRSIG (KSK) state for this key, and when it was last changed.

-z

Set the RRSIG (ZSK) state for this key, and when it was last changed.

Printing Options¶

dnssec-settime can also be used to print the timing metadata associated with a key.

-u: Print times in UNIX epoch format.
-p C/P/Psync/A/R/I/D/Dsync/all: Print a specific metadata value or set of metadata values. The -p option may be followed by one or more of the following letters or strings to indicate which value or values to print: C for the creation date, P for the publication date, Psync for the CDS and CDNSKEY publication date, A for the activation date, R for the revocation date, I for the inactivation date, D for the deletion date, and Dsync for the CDS and CDNSKEY deletion date To print all of the metadata, use -p all.

dnssec-importkey - import DNSKEY records from external systems so they can be managed¶

Synopsis¶

dnssec-importkey [-K directory] [-L ttl] [-P date/offset] [-P sync date/offset] [-D date/offset] [-D sync date/offset] [-h] [-v level] [-V] {keyfile}

dnssec-importkey {-f filename} [-K directory] [-L ttl] [-P date/offset] [-P sync date/offset] [-D date/offset] [-D sync date/offset] [-h] [-v level] [-V] [dnsname]

Description¶

dnssec-importkey reads a public DNSKEY record and generates a pair of .key/.private files. The DNSKEY record may be read from an existing .key file, in which case a corresponding .private file will be generated, or it may be read from any other file or from the standard input, in which case both .key and .private files will be generated.

The newly-created .private file does not contain private key data, and cannot be used for signing. However, having a .private file makes it possible to set publication (-P) and deletion (-D) times for the key, which means the public key can be added to and removed from the DNSKEY RRset on schedule even if the true private key is stored offline.

Options¶

-f filename

Zone file mode: instead of a public keyfile name, the argument is the DNS domain name of a zone master file, which can be read from file. If the domain name is the same as file, then it may be omitted.

If file is set to "-", then the zone data is read from the standard input.

-K directory

Sets the directory in which the key files are to reside.

-L ttl

Sets the default TTL to use for this key when it is converted into a DNSKEY RR. If the key is imported into a zone, this is the TTL that will be used for it, unless there was already a DNSKEY RRset in place, in which case the existing TTL would take precedence. Setting the default TTL to 0 or none removes it.

-h

Emit usage message and exit.

-v level

Sets the debugging level.

-V

Prints version information.

Timing Options¶

Dates can be expressed in the format YYYYMMDD or YYYYMMDDHHMMSS. If the argument begins with a ‘+’ or ‘-‘, it is interpreted as an offset from the present time. For convenience, if such an offset is followed by one of the suffixes ‘y’, ‘mo’, ‘w’, ‘d’, ‘h’, or ‘mi’, then the offset is computed in years (defined as 365 24-hour days, ignoring leap years), months (defined as 30 24-hour days), weeks, days, hours, or minutes, respectively. Without a suffix, the offset is computed in seconds. To explicitly prevent a date from being set, use ‘none’ or ‘never’.

-P date/offset: Sets the date on which a key is to be published to the zone. After that date, the key will be included in the zone but will not be used to sign it.
-P sync date/offset: Sets the date on which CDS and CDNSKEY records that match this key are to be published to the zone.
-D date/offset: Sets the date on which the key is to be deleted. After that date, the key will no longer be included in the zone. (It may remain in the key repository, however.)
-D sync date/offset: Sets the date on which the CDS and CDNSKEY records that match this key are to be deleted.

Files¶

A keyfile can be designed by the key identification Knnnn.+aaa+iiiii or the full file name Knnnn.+aaa+iiiii.key as generated by dnssec-keygen8.

dnssec-signzone - DNSSEC zone signing tool¶

Synopsis¶

dnssec-signzone [-a] [-c class] [-d directory] [-D] [-E engine] [-e end-time] [-f output-file] [-g] [-h] [-i interval] [-I input-format] [-j jitter] [-K directory] [-k key] [-L serial] [-M maxttl] [-N soa-serial-format] [-o origin] [-O output-format] [-P] [-Q] [-q] [-R] [-S] [-s start-time] [-T ttl] [-t] [-u] [-v level] [-V] [-X extended end-time] [-x] [-z] [-3 salt] [-H iterations] [-A] {zonefile} [key…]

Description¶

dnssec-signzone signs a zone. It generates NSEC and RRSIG records and produces a signed version of the zone. The security status of delegations from the signed zone (that is, whether the child zones are secure or not) is determined by the presence or absence of a keyset file for each child zone.

Options¶

-a

Verify all generated signatures.

-c class

Specifies the DNS class of the zone.

-C

Compatibility mode: Generate a keyset-zonename file in addition to dsset-zonename when signing a zone, for use by older versions of dnssec-signzone.

-d directory

Look for dsset- or keyset- files in directory.

-D

Output only those record types automatically managed by dnssec-signzone, i.e. RRSIG, NSEC, NSEC3 and NSEC3PARAM records. If smart signing (-S) is used, DNSKEY records are also included. The resulting file can be included in the original zone file with $INCLUDE. This option cannot be combined with -O raw, -O map, or serial number updating.

-E engine

When applicable, specifies the hardware to use for cryptographic operations, such as a secure key store used for signing.

When BIND is built with OpenSSL PKCS#11 support, this defaults to the string “pkcs11”, which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (–enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via “–with-pkcs11”.

-g

Generate DS records for child zones from dsset- or keyset- file. Existing DS records will be removed.

-K directory

Key repository: Specify a directory to search for DNSSEC keys. If not specified, defaults to the current directory.

-k key

Treat specified key as a key signing key ignoring any key flags. This option may be specified multiple times.

-M maxttl

Sets the maximum TTL for the signed zone. Any TTL higher than maxttl in the input zone will be reduced to maxttl in the output. This provides certainty as to the largest possible TTL in the signed zone, which is useful to know when rolling keys because it is the longest possible time before signatures that have been retrieved by resolvers will expire from resolver caches. Zones that are signed with this option should be configured to use a matching max-zone-ttl in named.conf. (Note: This option is incompatible with -D, because it modifies non-DNSSEC data in the output zone.)

-s start-time

Specify the date and time when the generated RRSIG records become valid. This can be either an absolute or relative time. An absolute start time is indicated by a number in YYYYMMDDHHMMSS notation; 20000530144500 denotes 14:45:00 UTC on May 30th, 2000. A relative start time is indicated by +N, which is N seconds from the current time. If no start-time is specified, the current time minus 1 hour (to allow for clock skew) is used.

-e end-time

Specify the date and time when the generated RRSIG records expire. As with start-time, an absolute time is indicated in YYYYMMDDHHMMSS notation. A time relative to the start time is indicated with +N, which is N seconds from the start time. A time relative to the current time is indicated with now+N. If no end-time is specified, 30 days from the start time is used as a default. end-time must be later than start-time.

-X extended end-time

Specify the date and time when the generated RRSIG records for the DNSKEY RRset will expire. This is to be used in cases when the DNSKEY signatures need to persist longer than signatures on other records; e.g., when the private component of the KSK is kept offline and the KSK signature is to be refreshed manually.

As with start-time, an absolute time is indicated in YYYYMMDDHHMMSS notation. A time relative to the start time is indicated with +N, which is N seconds from the start time. A time relative to the current time is indicated with now+N. If no extended end-time is specified, the value of end-time is used as the default. (end-time, in turn, defaults to 30 days from the start time.) extended end-time must be later than start-time.

-f output-file

The name of the output file containing the signed zone. The default is to append .signed to the input filename. If output-file is set to "-", then the signed zone is written to the standard output, with a default output format of “full”.

-h

Prints a short summary of the options and arguments to dnssec-signzone.

-V

Prints version information.

-i interval

When a previously-signed zone is passed as input, records may be resigned. The interval option specifies the cycle interval as an offset from the current time (in seconds). If a RRSIG record expires after the cycle interval, it is retained. Otherwise, it is considered to be expiring soon, and it will be replaced.

The default cycle interval is one quarter of the difference between the signature end and start times. So if neither end-time or start-time are specified, dnssec-signzone generates signatures that are valid for 30 days, with a cycle interval of 7.5 days. Therefore, if any existing RRSIG records are due to expire in less than 7.5 days, they would be replaced.

-I input-format

The format of the input zone file. Possible formats are "text" (default), "raw", and "map". This option is primarily intended to be used for dynamic signed zones so that the dumped zone file in a non-text format containing updates can be signed directly. The use of this option does not make much sense for non-dynamic zones.

-j jitter

When signing a zone with a fixed signature lifetime, all RRSIG records issued at the time of signing expires simultaneously. If the zone is incrementally signed, i.e. a previously-signed zone is passed as input to the signer, all expired signatures have to be regenerated at about the same time. The jitter option specifies a jitter window that will be used to randomize the signature expire time, thus spreading incremental signature regeneration over time.

Signature lifetime jitter also to some extent benefits validators and servers by spreading out cache expiration, i.e. if large numbers of RRSIGs don’t expire at the same time from all caches there will be less congestion than if all validators need to refetch at mostly the same time.

-L serial

When writing a signed zone to “raw” or “map” format, set the “source serial” value in the header to the specified serial number. (This is expected to be used primarily for testing purposes.)

-n ncpus

Specifies the number of threads to use. By default, one thread is started for each detected CPU.

-N soa-serial-format

The SOA serial number format of the signed zone. Possible formats are "keep" (default), "increment", "unixtime", and "date".

"keep": Do not modify the SOA serial number.
"increment": Increment the SOA serial number using RFC 1982 arithmetic.
"unixtime": Set the SOA serial number to the number of seconds since epoch.
"date": Set the SOA serial number to today’s date in YYYYMMDDNN format.

-o origin

The zone origin. If not specified, the name of the zone file is assumed to be the origin.

-O output-format

The format of the output file containing the signed zone. Possible formats are "text" (default), which is the standard textual representation of the zone; "full", which is text output in a format suitable for processing by external scripts; and "map", "raw", and "raw=N", which store the zone in binary formats for rapid loading by named. "raw=N" specifies the format version of the raw zone file: if N is 0, the raw file can be read by any version of named; if N is 1, the file can be read by release 9.9.0 or higher; the default is 1.

-P

Disable post sign verification tests.

The post sign verification test ensures that for each algorithm in use there is at least one non revoked self signed KSK key, that all revoked KSK keys are self signed, and that all records in the zone are signed by the algorithm. This option skips these tests.

-Q

Remove signatures from keys that are no longer active.

Normally, when a previously-signed zone is passed as input to the signer, and a DNSKEY record has been removed and replaced with a new one, signatures from the old key that are still within their validity period are retained. This allows the zone to continue to validate with cached copies of the old DNSKEY RRset. The -Q forces dnssec-signzone to remove signatures from keys that are no longer active. This enables ZSK rollover using the procedure described in RFC 4641#4.2.1.1 (“Pre-Publish Key Rollover”).

-q

Quiet mode: Suppresses unnecessary output. Without this option, when dnssec-signzone is run it will print to standard output the number of keys in use, the algorithms used to verify the zone was signed correctly and other status information, and finally the filename containing the signed zone. With it, that output is suppressed, leaving only the filename.

-R

Remove signatures from keys that are no longer published.

This option is similar to -Q, except it forces dnssec-signzone to signatures from keys that are no longer published. This enables ZSK rollover using the procedure described in RFC 4641#4.2.1.2 (“Double Signature Zone Signing Key Rollover”).

-S

Smart signing: Instructs dnssec-signzone to search the key repository for keys that match the zone being signed, and to include them in the zone if appropriate.

When a key is found, its timing metadata is examined to determine how it should be used, according to the following rules. Each successive rule takes priority over the prior ones:

If no timing metadata has been set for the key, the key is published in the zone and used to sign the zone.

If the key’s publication date is set and is in the past, the key is published in the zone.

If the key’s activation date is set and in the past, the key is published (regardless of publication date) and used to sign the zone.

If the key’s revocation date is set and in the past, and the key is published, then the key is revoked, and the revoked key is used to sign the zone.

If either of the key’s unpublication or deletion dates are set and in the past, the key is NOT published or used to sign the zone, regardless of any other metadata.

If key’s sync publication date is set and in the past, synchronization records (type CDS and/or CDNSKEY) are created.

If key’s sync deletion date is set and in the past, synchronization records (type CDS and/or CDNSKEY) are removed.

-T ttl

Specifies a TTL to be used for new DNSKEY records imported into the zone from the key repository. If not specified, the default is the TTL value from the zone’s SOA record. This option is ignored when signing without -S, since DNSKEY records are not imported from the key repository in that case. It is also ignored if there are any pre-existing DNSKEY records at the zone apex, in which case new records’ TTL values will be set to match them, or if any of the imported DNSKEY records had a default TTL value. In the event of a a conflict between TTL values in imported keys, the shortest one is used.

-t

Print statistics at completion.

-u

Update NSEC/NSEC3 chain when re-signing a previously signed zone. With this option, a zone signed with NSEC can be switched to NSEC3, or a zone signed with NSEC3 can be switch to NSEC or to NSEC3 with different parameters. Without this option, dnssec-signzone will retain the existing chain when re-signing.

-v level

Sets the debugging level.

-x

Only sign the DNSKEY, CDNSKEY, and CDS RRsets with key-signing keys, and omit signatures from zone-signing keys. (This is similar to the dnssec-dnskey-kskonly yes; zone option in named.)

-z

Ignore KSK flag on key when determining what to sign. This causes KSK-flagged keys to sign all records, not just the DNSKEY RRset. (This is similar to the update-check-ksk no; zone option in named.)

-3 salt

Generate an NSEC3 chain with the given hex encoded salt. A dash (salt) can be used to indicate that no salt is to be used when generating the NSEC3 chain.

-H iterations

When generating an NSEC3 chain, use this many iterations. The default is 10.

-A

When generating an NSEC3 chain set the OPTOUT flag on all NSEC3 records and do not generate NSEC3 records for insecure delegations.

Using this option twice (i.e., -AA) turns the OPTOUT flag off for all records. This is useful when using the -u option to modify an NSEC3 chain which previously had OPTOUT set.

zonefile

The file containing the zone to be signed.

key

Specify which keys should be used to sign the zone. If no keys are specified, then the zone will be examined for DNSKEY records at the zone apex. If these are found and there are matching private keys, in the current directory, then these will be used for signing.

Example¶

The following command signs the example.com zone with the ECDSAP256SHA256 key generated by key generated by dnssec-keygen (Kexample.com.+013+17247). Because the -S option is not being used, the zone’s keys must be in the master file (db.example.com). This invocation looks for dsset files, in the current directory, so that DS records can be imported from them (-g).

% dnssec-signzone -g -o example.com db.example.com \
Kexample.com.+013+17247
db.example.com.signed
%

In the above example, dnssec-signzone creates the file db.example.com.signed. This file should be referenced in a zone statement in a named.conf file.

This example re-signs a previously signed zone with default parameters. The private keys are assumed to be in the current directory.

% cp db.example.com.signed db.example.com
% dnssec-signzone -o example.com db.example.com
db.example.com.signed
%

dnssec-dsfromkey - DNSSEC DS RR generation tool¶

Synopsis¶

dnssec-dsfromkey [ -1 | -2 | -a alg ] [ -C ] [-T TTL] [-v level] [-K directory] {keyfile}

dnssec-dsfromkey [ -1 | -2 | -a alg ] [ -C ] [-T TTL] [-v level] [-c class] [-A] {-f file} [dnsname]

dnssec-dsfromkey [ -1 | -2 | -a alg ] [ -C ] [-T TTL] [-v level] [-c class] [-K directory] {-s} {dnsname}

dnssec-dsfromkey [ -h | -V ]

Description¶

The dnssec-dsfromkey command outputs DS (Delegation Signer) resource records (RRs), or CDS (Child DS) RRs with the -C option.

The input keys can be specified in a number of ways:

By default, dnssec-dsfromkey reads a key file named like Knnnn.+aaa+iiiii.key, as generated by dnssec-keygen.

With the -f file option, dnssec-dsfromkey reads keys from a zone file or partial zone file (which can contain just the DNSKEY records).

With the -s option, dnssec-dsfromkey reads a keyset- file, as generated by dnssec-keygen -C.

Options¶

-1

An abbreviation for -a SHA1

-2

An abbreviation for -a SHA-256

-a algorithm

Specify a digest algorithm to use when converting DNSKEY records to DS records. This option can be repeated, so that multiple DS records are created for each DNSKEY record.

The algorithm must be one of SHA-1, SHA-256, or SHA-384. These values are case insensitive, and the hyphen may be omitted. If no algorithm is specified, the default is SHA-256.

-A

Include ZSKs when generating DS records. Without this option, only keys which have the KSK flag set will be converted to DS records and printed. Useful only in -f zone file mode.

-c class

Specifies the DNS class (default is IN). Useful only in -s keyset or -f zone file mode.

-C

Generate CDS records rather than DS records.

-f file

Zone file mode: dnssec-dsfromkey’s final dnsname argument is the DNS domain name of a zone whose master file can be read from file. If the zone name is the same as file, then it may be omitted.

If file is "-", then the zone data is read from the standard input. This makes it possible to use the output of the dig command as input, as in:

dig dnskey example.com | dnssec-dsfromkey -f - example.com

-h

Prints usage information.

-K directory

Look for key files or keyset- files in directory.

-s

Keyset mode: dnssec-dsfromkey’s final dnsname argument is the DNS domain name used to locate a keyset- file.

-T TTL

Specifies the TTL of the DS records. By default the TTL is omitted.

-v level

Sets the debugging level.

-V

Prints version information.

Example¶

To build the SHA-256 DS RR from the Kexample.com.+003+26160 keyfile name, you can issue the following command:

dnssec-dsfromkey -2 Kexample.com.+003+26160

The command would print something like:

example.com. IN DS 26160 5 2 3A1EADA7A74B8D0BA86726B0C227AA85AB8BBD2B2004F41A868A54F0C5EA0B94

Files¶

The keyfile can be designated by the key identification Knnnn.+aaa+iiiii or the full file name Knnnn.+aaa+iiiii.key as generated by dnssec-keygen8.

The keyset file name is built from the directory, the string keyset- and the dnsname.

Caveat¶

A keyfile error can give a “file not found” even if the file exists.

dnssec-checkds - DNSSEC delegation consistency checking tool¶

Synopsis¶

dnssec-checkds [-ddig path] [-Ddsfromkey path] [-ffile] [-ldomain] [-sfile] {zone}

Description¶

dnssec-checkds verifies the correctness of Delegation Signer (DS) resource records for keys in a specified zone.

Options¶

-a algorithm

Specify a digest algorithm to use when converting the zones DNSKEY records to expected DS records. This option can be repeated, so that multiple records are checked for each DNSKEY record.

The algorithm must be one of SHA-1, SHA-256, or SHA-384. These values are case insensitive, and the hyphen may be omitted. If no algorithm is specified, the default is SHA-256.

-f file

If a file is specified, then the zone is read from that file to find the DNSKEY records. If not, then the DNSKEY records for the zone are looked up in the DNS.

-s file

Specifies a prepared dsset file, such as would be generated by dnssec-signzone, to use as a source for the DS RRset instead of querying the parent.

-d dig path

Specifies a path to a dig binary. Used for testing.

-D dsfromkey path

Specifies a path to a dnssec-dsfromkey binary. Used for testing.

dnssec-coverage - checks future DNSKEY coverage for a zone¶

Synopsis¶

dnssec-coverage [-Kdirectory] [-llength] [-ffile] [-dDNSKEY TTL] [-mmax TTL] [-rinterval] [-ccompilezone path] [-k] [-z] [zone…]

Description¶

dnssec-coverage verifies that the DNSSEC keys for a given zone or a set of zones have timing metadata set properly to ensure no future lapses in DNSSEC coverage.

If zone is specified, then keys found in the key repository matching that zone are scanned, and an ordered list is generated of the events scheduled for that key (i.e., publication, activation, inactivation, deletion). The list of events is walked in order of occurrence. Warnings are generated if any event is scheduled which could cause the zone to enter a state in which validation failures might occur: for example, if the number of published or active keys for a given algorithm drops to zero, or if a key is deleted from the zone too soon after a new key is rolled, and cached data signed by the prior key has not had time to expire from resolver caches.

If zone is not specified, then all keys in the key repository will be scanned, and all zones for which there are keys will be analyzed. (Note: This method of reporting is only accurate if all the zones that have keys in a given repository share the same TTL parameters.)

Options¶

-K directory

Sets the directory in which keys can be found. Defaults to the current working directory.

-f file

If a file is specified, then the zone is read from that file; the largest TTL and the DNSKEY TTL are determined directly from the zone data, and the -m and -d options do not need to be specified on the command line.

-l duration

The length of time to check for DNSSEC coverage. Key events scheduled further into the future than duration will be ignored, and assumed to be correct.

The value of duration can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

-m maximum TTL

Sets the value to be used as the maximum TTL for the zone or zones being analyzed when determining whether there is a possibility of validation failure. When a zone-signing key is deactivated, there must be enough time for the record in the zone with the longest TTL to have expired from resolver caches before that key can be purged from the DNSKEY RRset. If that condition does not apply, a warning will be generated.

The length of the TTL can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

This option is not necessary if the -f has been used to specify a zone file. If -f has been specified, this option may still be used; it will override the value found in the file.

If this option is not used and the maximum TTL cannot be retrieved from a zone file, a warning is generated and a default value of 1 week is used.

-d DNSKEY TTL

Sets the value to be used as the DNSKEY TTL for the zone or zones being analyzed when determining whether there is a possibility of validation failure. When a key is rolled (that is, replaced with a new key), there must be enough time for the old DNSKEY RRset to have expired from resolver caches before the new key is activated and begins generating signatures. If that condition does not apply, a warning will be generated.

The length of the TTL can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

This option is not necessary if -f has been used to specify a zone file from which the TTL of the DNSKEY RRset can be read, or if a default key TTL was set using ith the -L to dnssec-keygen. If either of those is true, this option may still be used; it will override the values found in the zone file or the key file.

If this option is not used and the key TTL cannot be retrieved from the zone file or the key file, then a warning is generated and a default value of 1 day is used.

-r resign interval

Sets the value to be used as the resign interval for the zone or zones being analyzed when determining whether there is a possibility of validation failure. This value defaults to 22.5 days, which is also the default in named. However, if it has been changed by the sig-validity-interval option in named.conf, then it should also be changed here.

The length of the interval can be set in seconds, or in larger units of time by adding a suffix: mi for minutes, h for hours, d for days, w for weeks, mo for months, y for years.

-k

Only check KSK coverage; ignore ZSK events. Cannot be used with -z.

-z

Only check ZSK coverage; ignore KSK events. Cannot be used with -k.

-c compilezone path

Specifies a path to a named-compilezone binary. Used for testing.

dnssec-keymgr - Ensures correct DNSKEY coverage based on a defined policy¶

Synopsis¶

:program:dnssec-keymgr [-Kdirectory] [-cfile] [-f] [-k] [-q] [-v] [-z] [-gpath] [-spath] [zone…]

Description¶

dnssec-keymgr is a high level Python wrapper to facilitate the key rollover process for zones handled by BIND. It uses the BIND commands for manipulating DNSSEC key metadata: dnssec-keygen and dnssec-settime.

DNSSEC policy can be read from a configuration file (default /etc/dnssec-policy.conf), from which the key parameters, publication and rollover schedule, and desired coverage duration for any given zone can be determined. This file may be used to define individual DNSSEC policies on a per-zone basis, or to set a “default” policy used for all zones.

When dnssec-keymgr runs, it examines the DNSSEC keys for one or more zones, comparing their timing metadata against the policies for those zones. If key settings do not conform to the DNSSEC policy (for example, because the policy has been changed), they are automatically corrected.

A zone policy can specify a duration for which we want to ensure the key correctness (coverage). It can also specify a rollover period (roll-period). If policy indicates that a key should roll over before the coverage period ends, then a successor key will automatically be created and added to the end of the key series.

If zones are specified on the command line, dnssec-keymgr will examine only those zones. If a specified zone does not already have keys in place, then keys will be generated for it according to policy.

If zones are not specified on the command line, then dnssec-keymgr will search the key directory (either the current working directory or the directory set by the -K option), and check the keys for all the zones represented in the directory.

Key times that are in the past will not be updated unless the -f is used (see below). Key inactivation and deletion times that are less than five minutes in the future will be delayed by five minutes.

It is expected that this tool will be run automatically and unattended (for example, by cron).

Options¶

-c file

If -c is specified, then the DNSSEC policy is read from file. (If not specified, then the policy is read from /etc/dnssec-policy.conf; if that file doesnt exist, a built-in global default policy is used.)

-f

Force: allow updating of key events even if they are already in the past. This is not recommended for use with zones in which keys have already been published. However, if a set of keys has been generated all of which have publication and activation dates in the past, but the keys have not been published in a zone as yet, then this option can be used to clean them up and turn them into a proper series of keys with appropriate rollover intervals.

-g keygen-path

Specifies a path to a dnssec-keygen binary. Used for testing. See also the -s option.

-h

Print the dnssec-keymgr help summary and exit.

-K directory

Sets the directory in which keys can be found. Defaults to the current working directory.

-k

Only apply policies to KSK keys. See also the -z option.

-q

Quiet: suppress printing of dnssec-keygen and dnssec-settime.

-s settime-path

Specifies a path to a dnssec-settime binary. Used for testing. See also the -g option.

-v

Print the dnssec-keymgr version and exit.

-z

Only apply policies to ZSK keys. See also the -k option.

Policy Configuration¶

The dnssec-policy.conf file can specify three kinds of policies:

· Policy classes (policyname{ ... };) can be inherited by zone policies or other policy classes; these can be used to create sets of different security profiles. For example, a policy class normal might specify 1024-bit key sizes, but a class extra might specify 2048 bits instead; extra would be used for zones that had unusually high security needs.

· Algorithm policies: (algorithm-policyalgorithm{ ... }; ) override default per-algorithm settings. For example, by default, RSASHA256 keys use 2048-bit key sizes for both KSK and ZSK. This can be modified using algorithm-policy, and the new key sizes would then be used for any key of type RSASHA256.

· Zone policies: (zonename{ ... }; ) set policy for a single zone by name. A zone policy can inherit a policy class by including a policy option. Zone names beginning with digits (i.e., 0-9) must be quoted. If a zone does not have its own policy then the “default” policy applies.

Options that can be specified in policies:

algorithm name;

The key algorithm. If no policy is defined, the default is RSASHA256.

coverage duration;

The length of time to ensure that keys will be correct; no action will be taken to create new keys to be activated after this time. This can be represented as a number of seconds, or as a duration using human-readable units (examples: “1y” or “6 months”). A default value for this option can be set in algorithm policies as well as in policy classes or zone policies. If no policy is configured, the default is six months.

directory path;

Specifies the directory in which keys should be stored.

key-size keytype size;

Specifies the number of bits to use in creating keys. The keytype is either “zsk” or “ksk”. A default value for this option can be set in algorithm policies as well as in policy classes or zone policies. If no policy is configured, the default is 2048 bits for RSA keys.

keyttl duration;

The key TTL. If no policy is defined, the default is one hour.

post-publish keytype duration;

How long after inactivation a key should be deleted from the zone. Note: If roll-period is not set, this value is ignored. The keytype is either “zsk” or “ksk”. A default duration for this option can be set in algorithm policies as well as in policy classes or zone policies. The default is one month.

pre-publish keytype duration;

How long before activation a key should be published. Note: If roll-period is not set, this value is ignored. The keytype is either “zsk” or “ksk”. A default duration for this option can be set in algorithm policies as well as in policy classes or zone policies. The default is one month.

roll-period keytype duration;

How frequently keys should be rolled over. The keytype is either “zsk” or “ksk”. A default duration for this option can be set in algorithm policies as well as in policy classes or zone policies. If no policy is configured, the default is one year for ZSKs. KSKs do not roll over by default.

standby keytype number;

Not yet implemented.

Remaining Work¶

· Enable scheduling of KSK rollovers using the -P sync and -D sync options to dnssec-keygen and dnssec-settime. Check the parent zone (as in dnssec-checkds) to determine when its safe for the key to roll.

· Allow configuration of standby keys and use of the REVOKE bit, for keys that use RFC 5011 semantics.

filter-aaaa.so - filter AAAA in DNS responses when A is present¶

Synopsis¶

plugin query “filter-aaaa.so” [{ parameters }];

Description¶

filter-aaaa.so is a query plugin module for named, enabling named to omit some IPv6 addresses when responding to clients.

Until BIND 9.12, this feature was implemented natively in named and enabled with the filter-aaaa ACL and the filter-aaaa-on-v4 and filter-aaaa-on-v6 options. These options are now deprecated in named.conf, but can be passed as parameters to the filter-aaaa.so plugin, for example:

plugin query "/usr/local/lib/filter-aaaa.so" {
        filter-aaaa-on-v4 yes;
        filter-aaaa-on-v6 yes;
        filter-aaaa { 192.0.2.1; 2001:db8:2::1; };
};

This module is intended to aid transition from IPv4 to IPv6 by withholding IPv6 addresses from DNS clients which are not connected to the IPv6 Internet, when the name being looked up has an IPv4 address available. Use of this module is not recommended unless absolutely necessary.

Note: This mechanism can erroneously cause other servers not to give AAAA records to their clients. If a recursing server with both IPv6 and IPv4 network connections queries an authoritative server using this mechanism via IPv4, it will be denied AAAA records even if its client is using IPv6.

Options¶

filter-aaaa

Specifies a list of client addresses for which AAAA filtering is to be applied. The default is any.

filter-aaaa-on-v4

If set to yes, the DNS client is at an IPv4 address, in filter-aaaa, and if the response does not include DNSSEC signatures, then all AAAA records are deleted from the response. This filtering applies to all responses and not only authoritative responses.

If set to break-dnssec, then AAAA records are deleted even when DNSSEC is enabled. As suggested by the name, this causes the response to fail to verify, because the DNSSEC protocol is designed to detect deletions.

This mechanism can erroneously cause other servers not to give AAAA records to their clients. A recursing server with both IPv6 and IPv4 network connections that queries an authoritative server using this mechanism via IPv4 will be denied AAAA records even if its client is using IPv6.

filter-aaaa-on-v6

Identical to filter-aaaa-on-v4, except it filters AAAA responses to queries from IPv6 clients instead of IPv4 clients. To filter all responses, set both options to yes.

ddns-confgen - ddns key generation tool¶

Synopsis¶

tsig-keygen [-a algorithm] [-h] [-r randomfile] [-s name]

ddns-confgen [-a algorithm] [-h] [-k keyname] [-q] [-r randomfile] [-s name] [-z zone]

Description¶

tsig-keygen and ddns-confgen are invocation methods for a utility that generates keys for use in TSIG signing. The resulting keys can be used, for example, to secure dynamic DNS updates to a zone or for the rndc command channel.

When run as tsig-keygen, a domain name can be specified on the command line which will be used as the name of the generated key. If no name is specified, the default is tsig-key.

When run as ddns-confgen, the generated key is accompanied by configuration text and instructions that can be used with nsupdate and named when setting up dynamic DNS, including an example update-policy statement. (This usage similar to the rndc-confgen command for setting up command channel security.)

Note that named itself can configure a local DDNS key for use with nsupdate -l: it does this when a zone is configured with update-policy local;. ddns-confgen is only needed when a more elaborate configuration is required: for instance, if nsupdate is to be used from a remote system.

Options¶

-a algorithm: Specifies the algorithm to use for the TSIG key. Available choices are: hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384 and hmac-sha512. The default is hmac-sha256. Options are case-insensitive, and the “hmac-” prefix may be omitted.
-h: Prints a short summary of options and arguments.
-k keyname: Specifies the key name of the DDNS authentication key. The default is ddns-key when neither the -s nor -z option is specified; otherwise, the default is ddns-key as a separate label followed by the argument of the option, e.g., ddns-key.example.com. The key name must have the format of a valid domain name, consisting of letters, digits, hyphens and periods.
-q: (ddns-confgen only.) Quiet mode: Print only the key, with no explanatory text or usage examples; This is essentially identical to tsig-keygen.
-s name: (ddns-confgen only.) Generate configuration example to allow dynamic updates of a single hostname. The example named.conf text shows how to set an update policy for the specified name using the “name” nametype. The default key name is ddns-key.name. Note that the “self” nametype cannot be used, since the name to be updated may differ from the key name. This option cannot be used with the -z option.
-z zone: (ddns-confgen only.) Generate configuration example to allow dynamic updates of a zone: The example named.conf text shows how to set an update policy for the specified zone using the “zonesub” nametype, allowing updates to all subdomain names within that zone. This option cannot be used with the -s option.

rndc-confgen - rndc key generation tool¶

Synopsis¶

rndc-confgen [-a] [-A algorithm] [-b keysize] [-c keyfile] [-h] [-k keyname] [-p port] [-s address] [-t chrootdir] [-u user]

Description¶

rndc-confgen generates configuration files for rndc. It can be used as a convenient alternative to writing the rndc.conf file and the corresponding controls and key statements in named.conf by hand. Alternatively, it can be run with the -a option to set up a rndc.key file and avoid the need for a rndc.conf file and a controls statement altogether.

Arguments¶

-a

Do automatic rndc configuration. This creates a file rndc.key in /etc (or whatever sysconfdir was specified as when BIND was built) that is read by both rndc and named on startup. The rndc.key file defines a default command channel and authentication key allowing rndc to communicate with named on the local host with no further configuration.

Running rndc-confgen -a allows BIND 9 and rndc to be used as drop-in replacements for BIND 8 and ndc, with no changes to the existing BIND 8 named.conf file.

If a more elaborate configuration than that generated by rndc-confgen -a is required, for example if rndc is to be used remotely, you should run rndc-confgen without the -a option and set up a rndc.conf and named.conf as directed.

-A algorithm

Specifies the algorithm to use for the TSIG key. Available choices are: hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384 and hmac-sha512. The default is hmac-sha256.

-b keysize

Specifies the size of the authentication key in bits. Must be between 1 and 512 bits; the default is the hash size.

-c keyfile

Used with the -a option to specify an alternate location for rndc.key.

-h

Prints a short summary of the options and arguments to rndc-confgen.

-k keyname

Specifies the key name of the rndc authentication key. This must be a valid domain name. The default is rndc-key.

-p port

Specifies the command channel port where named listens for connections from rndc. The default is 953.

-s address

Specifies the IP address where named listens for command channel connections from rndc. The default is the loopback address 127.0.0.1.

-t chrootdir

Used with the -a option to specify a directory where named will run chrooted. An additional copy of the rndc.key will be written relative to this directory so that it will be found by the chrooted named.

-u user

Used with the -a option to set the owner of the rndc.key file generated. If -t is also specified only the file in the chroot area has its owner changed.

Examples¶

To allow rndc to be used with no manual configuration, run

rndc-confgen -a

To print a sample rndc.conf file and corresponding controls and key statements to be manually inserted into named.conf, run

rndc-confgen

delv - DNS lookup and validation utility¶

Synopsis¶

delv [@server] [ [-4] | [-6] ] [-a anchor-file] [-b address] [-c class] [-d level] [-i] [-m] [-p port#] [-q name] [-t type] [-x addr] [name] [type] [class] [queryopt…]

delv [-h]

delv [-v]

delv [queryopt…] [query…]

Description¶

delv is a tool for sending DNS queries and validating the results, using the same internal resolver and validator logic as named.

delv will send to a specified name server all queries needed to fetch and validate the requested data; this includes the original requested query, subsequent queries to follow CNAME or DNAME chains, and queries for DNSKEY, and DS records to establish a chain of trust for DNSSEC validation. It does not perform iterative resolution, but simulates the behavior of a name server configured for DNSSEC validating and forwarding.

By default, responses are validated using built-in DNSSEC trust anchor for the root zone (“.”). Records returned by delv are either fully validated or were not signed. If validation fails, an explanation of the failure is included in the output; the validation process can be traced in detail. Because delv does not rely on an external server to carry out validation, it can be used to check the validity of DNS responses in environments where local name servers may not be trustworthy.

Unless it is told to query a specific name server, delv will try each of the servers listed in /etc/resolv.conf. If no usable server addresses are found, delv will send queries to the localhost addresses (127.0.0.1 for IPv4, ::1 for IPv6).

When no command line arguments or options are given, delv will perform an NS query for “.” (the root zone).

Simple Usage¶

A typical invocation of delv looks like:

delv @server name type

where:

server

is the name or IP address of the name server to query. This can be an IPv4 address in dotted-decimal notation or an IPv6 address in colon-delimited notation. When the supplied server argument is a hostname, delv resolves that name before querying that name server (note, however, that this initial lookup is not validated by DNSSEC).

If no server argument is provided, delv consults /etc/resolv.conf; if an address is found there, it queries the name server at that address. If either of the -4 or -6 options are in use, then only addresses for the corresponding transport will be tried. If no usable addresses are found, delv will send queries to the localhost addresses (127.0.0.1 for IPv4, ::1 for IPv6).

name

is the domain name to be looked up.

type

indicates what type of query is required MDASH ANY, A, MX, etc. type can be any valid query type. If no type argument is supplied, delv will perform a lookup for an A record.

Options¶

-a anchor-file

Specifies a file from which to read DNSSEC trust anchors. The default is /etc/bind.keys, which is included with BIND 9 and contains one or more trust anchors for the root zone (“.”).

Keys that do not match the root zone name are ignored. An alternate key name can be specified using the +root=NAME options.

Note: When reading the trust anchor file, delv treat trust-anchors initial-key and static-key identically. That is, for a managed key, it is the initial key that is trusted; RFC 5011 key management is not supported. delv will not consult the managed-keys database maintained by named. This means that if either of the keys in /etc/bind.keys is revoked and rolled over, it will be necessary to update /etc/bind.keys to use DNSSEC validation in delv.

-b address

Sets the source IP address of the query to address. This must be a valid address on one of the host’s network interfaces or “0.0.0.0” or “::”. An optional source port may be specified by appending “#<port>”

-c class

Sets the query class for the requested data. Currently, only class “IN” is supported in delv and any other value is ignored.

-d level

Set the systemwide debug level to level. The allowed range is from 0 to 99. The default is 0 (no debugging). Debugging traces from delv become more verbose as the debug level increases. See the +mtrace, +rtrace, and +vtrace options below for additional debugging details.

-h

Display the delv help usage output and exit.

-i

Insecure mode. This disables internal DNSSEC validation. (Note, however, this does not set the CD bit on upstream queries. If the server being queried is performing DNSSEC validation, then it will not return invalid data; this can cause delv to time out. When it is necessary to examine invalid data to debug a DNSSEC problem, use dig +cd.)

-m

Enables memory usage debugging.

-p port#

Specifies a destination port to use for queries instead of the standard DNS port number 53. This option would be used with a name server that has been configured to listen for queries on a non-standard port number.

-q name

Sets the query name to name. While the query name can be specified without using the -q, it is sometimes necessary to disambiguate names from types or classes (for example, when looking up the name “ns”, which could be misinterpreted as the type NS, or “ch”, which could be misinterpreted as class CH).

-t type

Sets the query type to type, which can be any valid query type supported in BIND 9 except for zone transfer types AXFR and IXFR. As with -q, this is useful to distinguish query name type or class when they are ambiguous. it is sometimes necessary to disambiguate names from types.

The default query type is “A”, unless the -x option is supplied to indicate a reverse lookup, in which case it is “PTR”.

-v

Print the delv version and exit.

-x addr

Performs a reverse lookup, mapping an addresses to a name. addr is an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. When -x is used, there is no need to provide the name or type arguments. delv automatically performs a lookup for a name like 11.12.13.10.in-addr.arpa and sets the query type to PTR. IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.

-4

Forces delv to only use IPv4.

-6

Forces delv to only use IPv6.

Query Options¶

delv provides a number of query options which affect the way results are displayed, and in some cases the way lookups are performed.

Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option. These may be preceded by the string no to negate the meaning of that keyword. Other keywords assign values to options like the timeout interval. They have the form +keyword=value. The query options are:

+[no]cdflag

Controls whether to set the CD (checking disabled) bit in queries sent by delv. This may be useful when troubleshooting DNSSEC problems from behind a validating resolver. A validating resolver will block invalid responses, making it difficult to retrieve them for analysis. Setting the CD flag on queries will cause the resolver to return invalid responses, which delv can then validate internally and report the errors in detail.

+[no]class

Controls whether to display the CLASS when printing a record. The default is to display the CLASS.

+[no]ttl

Controls whether to display the TTL when printing a record. The default is to display the TTL.

+[no]rtrace

Toggle resolver fetch logging. This reports the name and type of each query sent by delv in the process of carrying out the resolution and validation process: this includes including the original query and all subsequent queries to follow CNAMEs and to establish a chain of trust for DNSSEC validation.

This is equivalent to setting the debug level to 1 in the “resolver” logging category. Setting the systemwide debug level to 1 using the -d option will product the same output (but will affect other logging categories as well).

+[no]mtrace

Toggle message logging. This produces a detailed dump of the responses received by delv in the process of carrying out the resolution and validation process.

This is equivalent to setting the debug level to 10 for the “packets” module of the “resolver” logging category. Setting the systemwide debug level to 10 using the -d option will produce the same output (but will affect other logging categories as well).

+[no]vtrace

Toggle validation logging. This shows the internal process of the validator as it determines whether an answer is validly signed, unsigned, or invalid.

This is equivalent to setting the debug level to 3 for the “validator” module of the “dnssec” logging category. Setting the systemwide debug level to 3 using the -d option will produce the same output (but will affect other logging categories as well).

+[no]short

Provide a terse answer. The default is to print the answer in a verbose form.

+[no]comments

Toggle the display of comment lines in the output. The default is to print comments.

+[no]rrcomments

Toggle the display of per-record comments in the output (for example, human-readable key information about DNSKEY records). The default is to print per-record comments.

+[no]crypto

Toggle the display of cryptographic fields in DNSSEC records. The contents of these field are unnecessary to debug most DNSSEC validation failures and removing them makes it easier to see the common failures. The default is to display the fields. When omitted they are replaced by the string “[omitted]” or in the DNSKEY case the key id is displayed as the replacement, e.g. “[ key id = value ]”.

+[no]trust

Controls whether to display the trust level when printing a record. The default is to display the trust level.

+[no]split[=W]

Split long hex- or base64-formatted fields in resource records into chunks of W characters (where W is rounded up to the nearest multiple of 4). +nosplit or +split=0 causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active.

+[no]all

Set or clear the display options +[no]comments, +[no]rrcomments, and +[no]trust as a group.

+[no]multiline

Print long records (such as RRSIG, DNSKEY, and SOA records) in a verbose multi-line format with human-readable comments. The default is to print each record on a single line, to facilitate machine parsing of the delv output.

+[no]dnssec

Indicates whether to display RRSIG records in the delv output. The default is to do so. Note that (unlike in dig) this does not control whether to request DNSSEC records or whether to validate them. DNSSEC records are always requested, and validation will always occur unless suppressed by the use of -i or +noroot.

+[no]root[=ROOT]

Indicates whether to perform conventional DNSSEC validation, and if so, specifies the name of a trust anchor. The default is to validate using a trust anchor of “.” (the root zone), for which there is a built-in key. If specifying a different trust anchor, then -a must be used to specify a file containing the key.

+[no]tcp

Controls whether to use TCP when sending queries. The default is to use UDP unless a truncated response has been received.

+[no]unknownformat

Print all RDATA in unknown RR type presentation format (RFC 3597). The default is to print RDATA for known types in the type’s presentation format.

+[no]yaml

Print response data in YAML format.

Files¶

/etc/bind.keys

/etc/resolv.conf

nsupdate - dynamic DNS update utility¶

Synopsis¶

Description¶

nsupdate is used to submit Dynamic DNS Update requests as defined in RFC 2136 to a name server. This allows resource records to be added or removed from a zone without manually editing the zone file. A single update request can contain requests to add or remove more than one resource record.

Zones that are under dynamic control via nsupdate or a DHCP server should not be edited by hand. Manual edits could conflict with dynamic updates and cause data to be lost.

The resource records that are dynamically added or removed with nsupdate have to be in the same zone. Requests are sent to the zone’s master server. This is identified by the MNAME field of the zone’s SOA record.

Transaction signatures can be used to authenticate the Dynamic DNS updates. These use the TSIG resource record type described in RFC 2845 or the SIG(0) record described in RFC 2535 and RFC 2931 or GSS-TSIG as described in RFC 3645.

TSIG relies on a shared secret that should only be known to nsupdate and the name server. For instance, suitable key and server statements would be added to /etc/named.conf so that the name server can associate the appropriate secret key and algorithm with the IP address of the client application that will be using TSIG authentication. You can use ddns-confgen to generate suitable configuration fragments. nsupdate uses the -y or -k options to provide the TSIG shared secret. These options are mutually exclusive.

SIG(0) uses public key cryptography. To use a SIG(0) key, the public key must be stored in a KEY record in a zone served by the name server.

GSS-TSIG uses Kerberos credentials. Standard GSS-TSIG mode is switched on with the -g flag. A non-standards-compliant variant of GSS-TSIG used by Windows 2000 can be switched on with the -o flag.

Options¶

-4

Use IPv4 only.

-6

Use IPv6 only.

-d

Debug mode. This provides tracing information about the update requests that are made and the replies received from the name server.

-D

Extra debug mode.

-i

Force interactive mode, even when standard input is not a terminal.

-k keyfile

The file containing the TSIG authentication key. Keyfiles may be in two formats: a single file containing a named.conf-format key statement, which may be generated automatically by ddns-confgen, or a pair of files whose names are of the format K{name}.+157.+{random}.key and K{name}.+157.+{random}.private, which can be generated by dnssec-keygen. The -k may also be used to specify a SIG(0) key used to authenticate Dynamic DNS update requests. In this case, the key specified is not an HMAC-MD5 key.

-l

Local-host only mode. This sets the server address to localhost (disabling the server so that the server address cannot be overridden). Connections to the local server will use a TSIG key found in /var/run/named/session.key, which is automatically generated by named if any local master zone has set update-policy to local. The location of this key file can be overridden with the -k option.

-L level

Set the logging debug level. If zero, logging is disabled.

-p port

Set the port to use for connections to a name server. The default is 53.

-P

Print the list of private BIND-specific resource record types whose format is understood by nsupdate. See also the -T option.

-r udpretries

The number of UDP retries. The default is 3. If zero, only one update request will be made.

-t timeout

The maximum time an update request can take before it is aborted. The default is 300 seconds. Zero can be used to disable the timeout.

-T

Print the list of IANA standard resource record types whose format is understood by nsupdate. nsupdate will exit after the lists are printed. The -T option can be combined with the -P option.

Other types can be entered using “TYPEXXXXX” where “XXXXX” is the decimal value of the type with no leading zeros. The rdata, if present, will be parsed using the UNKNOWN rdata format, (<backslash> <hash> <space> <length> <space> <hexstring>).

-u udptimeout

The UDP retry interval. The default is 3 seconds. If zero, the interval will be computed from the timeout interval and number of UDP retries.

-v

Use TCP even for small update requests. By default, nsupdate uses UDP to send update requests to the name server unless they are too large to fit in a UDP request in which case TCP will be used. TCP may be preferable when a batch of update requests is made.

-V

Print the version number and exit.

-y [hmac:]keyname:secret

Literal TSIG authentication key. keyname is the name of the key, and secret is the base64 encoded shared secret. hmac is the name of the key algorithm; valid choices are hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, or hmac-sha512. If hmac is not specified, the default is hmac-md5 or if MD5 was disabled hmac-sha256.

NOTE: Use of the -y option is discouraged because the shared secret is supplied as a command line argument in clear text. This may be visible in the output from ps1 or in a history file maintained by the user’s shell.

Input Format¶

nsupdate reads input from filename or standard input. Each command is supplied on exactly one line of input. Some commands are for administrative purposes. The others are either update instructions or prerequisite checks on the contents of the zone. These checks set conditions that some name or set of resource records (RRset) either exists or is absent from the zone. These conditions must be met if the entire update request is to succeed. Updates will be rejected if the tests for the prerequisite conditions fail.

Every update request consists of zero or more prerequisites and zero or more updates. This allows a suitably authenticated update request to proceed if some specified resource records are present or missing from the zone. A blank input line (or the send command) causes the accumulated commands to be sent as one Dynamic DNS update request to the name server.

The command formats and their meaning are as follows:

server servername port: Sends all dynamic update requests to the name server servername. When no server statement is provided, nsupdate will send updates to the master server of the correct zone. The MNAME field of that zone’s SOA record will identify the master server for that zone. port is the port number on servername where the dynamic update requests get sent. If no port number is specified, the default DNS port number of 53 is used.
local address port: Sends all dynamic update requests using the local address. When no local statement is provided, nsupdate will send updates using an address and port chosen by the system. port can additionally be used to make requests come from a specific port. If no port number is specified, the system will assign one.
zone zonename: Specifies that all updates are to be made to the zone zonename. If no zone statement is provided, nsupdate will attempt determine the correct zone to update based on the rest of the input.
class classname: Specify the default class. If no class is specified, the default class is IN.
ttl seconds: Specify the default time to live for records to be added. The value none will clear the default ttl.
key hmac:keyname secret: Specifies that all updates are to be TSIG-signed using the keyname secret pair. If hmac is specified, then it sets the signing algorithm in use; the default is hmac-md5 or if MD5 was disabled hmac-sha256. The key command overrides any key specified on the command line via -y or -k.
gsstsig: Use GSS-TSIG to sign the updated. This is equivalent to specifying -g on the command line.
oldgsstsig: Use the Windows 2000 version of GSS-TSIG to sign the updated. This is equivalent to specifying -o on the command line.
realm [realm_name]: When using GSS-TSIG use realm_name rather than the default realm in krb5.conf. If no realm is specified the saved realm is cleared.
check-names [yes_or_no]: Turn on or off check-names processing on records to be added. Check-names has no effect on prerequisites or records to be deleted. By default check-names processing is on. If check-names processing fails the record will not be added to the UPDATE message.
prereq nxdomain domain-name: Requires that no resource record of any type exists with name domain-name.
prereq yxdomain domain-name: Requires that domain-name exists (has as at least one resource record, of any type).
prereq nxrrset domain-name class type: Requires that no resource record exists of the specified type, class and domain-name. If class is omitted, IN (internet) is assumed.
prereq yxrrset domain-name class type: This requires that a resource record of the specified type, class and domain-name must exist. If class is omitted, IN (internet) is assumed.
prereq yxrrset domain-name class type data: The data from each set of prerequisites of this form sharing a common type, class, and domain-name are combined to form a set of RRs. This set of RRs must exactly match the set of RRs existing in the zone at the given type, class, and domain-name. The data are written in the standard text representation of the resource record’s RDATA.
update delete domain-name ttl class type data: Deletes any resource records named domain-name. If type and data is provided, only matching resource records will be removed. The internet class is assumed if class is not supplied. The ttl is ignored, and is only allowed for compatibility.
update add domain-name ttl class type data: Adds a new resource record with the specified ttl, class and data.
show: Displays the current message, containing all of the prerequisites and updates specified since the last send.
send: Sends the current message. This is equivalent to entering a blank line.
answer: Displays the answer.
debug: Turn on debugging.
version: Print version number.
help: Print a list of commands.

Lines beginning with a semicolon are comments and are ignored.

Examples¶

The examples below show how nsupdate could be used to insert and delete resource records from the example.com zone. Notice that the input in each example contains a trailing blank line so that a group of commands are sent as one dynamic update request to the master name server for example.com.

# nsupdate
> update delete oldhost.example.com A
> update add newhost.example.com 86400 A 172.16.1.1
> send

Any A records for oldhost.example.com are deleted. And an A record for newhost.example.com with IP address 172.16.1.1 is added. The newly-added record has a 1 day TTL (86400 seconds).

# nsupdate
> prereq nxdomain nickname.example.com
> update add nickname.example.com 86400 CNAME somehost.example.com
> send

The prerequisite condition gets the name server to check that there are no resource records of any type for nickname.example.com. If there are, the update request fails. If this name does not exist, a CNAME for it is added. This ensures that when the CNAME is added, it cannot conflict with the long-standing rule in RFC 1034 that a name must not exist as any other record type if it exists as a CNAME. (The rule has been updated for DNSSEC in RFC 2535 to allow CNAMEs to have RRSIG, DNSKEY and NSEC records.)

Files¶

/etc/resolv.conf: used to identify default name server
/var/run/named/session.key: sets the default TSIG key for use in local-only mode
K{name}.+157.+{random}.key: base-64 encoding of HMAC-MD5 key created by dnssec-keygen8.
K{name}.+157.+{random}.private: base-64 encoding of HMAC-MD5 key created by dnssec-keygen8.

Bugs¶

The TSIG key is redundantly stored in two separate files. This is a consequence of nsupdate using the DST library for its cryptographic operations, and may change in future releases.

host - DNS lookup utility¶

Synopsis¶

host [-aACdlnrsTUwv] [-c class] [-N ndots] [-p port] [-R number] [-t type] [-W wait] [-m flag] [ [-4] | [-6] ] [-v] [-V] {name} [server]

Description¶

host is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa. When no arguments or options are given, host prints a short summary of its command line arguments and options.

name is the domain name that is to be looked up. It can also be a dotted-decimal IPv4 address or a colon-delimited IPv6 address, in which case host will by default perform a reverse lookup for that address. server is an optional argument which is either the name or IP address of the name server that host should query instead of the server or servers listed in /etc/resolv.conf.

Options¶

-4

Use IPv4 only for query transport. See also the -6 option.

-6

Use IPv6 only for query transport. See also the -4 option.

-a

“All”. The -a option is normally equivalent to -v -t ANY. It also affects the behaviour of the -l list zone option.

-A

“Almost all”. The -A option is equivalent to -a except RRSIG, NSEC, and NSEC3 records are omitted from the output.

-c class

Query class: This can be used to lookup HS (Hesiod) or CH (Chaosnet) class resource records. The default class is IN (Internet).

-C

Check consistency: host will query the SOA records for zone name from all the listed authoritative name servers for that zone. The list of name servers is defined by the NS records that are found for the zone.

-d

Print debugging traces. Equivalent to the -v verbose option.

-l

List zone: The host command performs a zone transfer of zone name and prints out the NS, PTR and address records (A/AAAA).

Together, the -l -a options print all records in the zone.

-N ndots

The number of dots that have to be in name for it to be considered absolute. The default value is that defined using the ndots statement in /etc/resolv.conf, or 1 if no ndots statement is present. Names with fewer dots are interpreted as relative names and will be searched for in the domains listed in the search or domain directive in /etc/resolv.conf.

-p port

Specify the port on the server to query. The default is 53.

-r

Non-recursive query: Setting this option clears the RD (recursion desired) bit in the query. This should mean that the name server receiving the query will not attempt to resolve name. The -r option enables host to mimic the behavior of a name server by making non-recursive queries and expecting to receive answers to those queries that can be referrals to other name servers.

-R number

Number of retries for UDP queries: If number is negative or zero, the number of retries will default to 1. The default value is 1, or the value of the attempts option in /etc/resolv.conf, if set.

-s

Do not send the query to the next nameserver if any server responds with a SERVFAIL response, which is the reverse of normal stub resolver behavior.

-t type

Query type: The type argument can be any recognized query type: CNAME, NS, SOA, TXT, DNSKEY, AXFR, etc.

When no query type is specified, host automatically selects an appropriate query type. By default, it looks for A, AAAA, and MX records. If the -C option is given, queries will be made for SOA records. If name is a dotted-decimal IPv4 address or colon-delimited IPv6 address, host will query for PTR records.

If a query type of IXFR is chosen the starting serial number can be specified by appending an equal followed by the starting serial number (like -t IXFR=12345678).

-T; -U

TCP/UDP: By default, host uses UDP when making queries. The -T option makes it use a TCP connection when querying the name server. TCP will be automatically selected for queries that require it, such as zone transfer (AXFR) requests. Type ANY queries default to TCP but can be forced to UDP initially using -U.

-m flag

Memory usage debugging: the flag can be record, usage, or trace. You can specify the -m option more than once to set multiple flags.

-v

Verbose output. Equivalent to the -d debug option. Verbose output can also be enabled by setting the debug option in /etc/resolv.conf.

-V

Print the version number and exit.

-w

Wait forever: The query timeout is set to the maximum possible. See also the -W option.

-W wait

Timeout: Wait for up to wait seconds for a reply. If wait is less than one, the wait interval is set to one second.

By default, host will wait for 5 seconds for UDP responses and 10 seconds for TCP connections. These defaults can be overridden by the timeout option in /etc/resolv.conf.

IDN Support¶

If host has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. host appropriately converts character encoding of domain name before sending a request to DNS server or displaying a reply from the server. If you’d like to turn off the IDN support for some reason, define the IDN_DISABLE environment variable. The IDN support is disabled if the variable is set when host runs.

Files¶

/etc/resolv.conf

dig - DNS lookup utility¶

Synopsis¶

dig [@server] [-b address] [-c class] [-f filename] [-k filename] [-m] [-p port#] [-q name] [-t type] [-v] [-x addr] [-y [hmac:]name:key] [ [-4] | [-6] ] [name] [type] [class] [queryopt…]

dig [-h]

dig [global-queryopt…] [query…]

Description¶

dig is a flexible tool for interrogating DNS name servers. It performs DNS lookups and displays the answers that are returned from the name server(s) that were queried. Most DNS administrators use dig to troubleshoot DNS problems because of its flexibility, ease of use and clarity of output. Other lookup tools tend to have less functionality than dig.

Although dig is normally used with command-line arguments, it also has a batch mode of operation for reading lookup requests from a file. A brief summary of its command-line arguments and options is printed when the -h option is given. Unlike earlier versions, the BIND 9 implementation of dig allows multiple lookups to be issued from the command line.

Unless it is told to query a specific name server, dig will try each of the servers listed in /etc/resolv.conf. If no usable server addresses are found, dig will send the query to the local host.

When no command line arguments or options are given, dig will perform an NS query for “.” (the root).

It is possible to set per-user defaults for dig via ${HOME}/.digrc. This file is read and any options in it are applied before the command line arguments. The -r option disables this feature, for scripts that need predictable behaviour.

The IN and CH class names overlap with the IN and CH top level domain names. Either use the -t and -c options to specify the type and class, use the -q the specify the domain name, or use “IN.” and “CH.” when looking up these top level domains.

Simple Usage¶

A typical invocation of dig looks like:

dig @server name type

where:

server

is the name or IP address of the name server to query. This can be an IPv4 address in dotted-decimal notation or an IPv6 address in colon-delimited notation. When the supplied server argument is a hostname, dig resolves that name before querying that name server.

If no server argument is provided, dig consults /etc/resolv.conf; if an address is found there, it queries the name server at that address. If either of the -4 or -6 options are in use, then only addresses for the corresponding transport will be tried. If no usable addresses are found, dig will send the query to the local host. The reply from the name server that responds is displayed.

name

is the name of the resource record that is to be looked up.

type

indicates what type of query is required MDASH ANY, A, MX, SIG, etc. type can be any valid query type. If no type argument is supplied, dig will perform a lookup for an A record.

Options¶

-4

Use IPv4 only.

-6

Use IPv6 only.

-b address[#port]

Set the source IP address of the query. The address must be a valid address on one of the host’s network interfaces, or “0.0.0.0” or “::”. An optional port may be specified by appending “#<port>”

-c class

Set the query class. The default class is IN; other classes are HS for Hesiod records or CH for Chaosnet records.

-f file

Batch mode: dig reads a list of lookup requests to process from the given file. Each line in the file should be organized in the same way they would be presented as queries to dig using the command-line interface.

-k keyfile

Sign queries using TSIG using a key read from the given file. Key files can be generated using tsig-keygen8. When using TSIG authentication with dig, the name server that is queried needs to know the key and algorithm that is being used. In BIND, this is done by providing appropriate key and server statements in named.conf.

-m

Enable memory usage debugging.

-p port

Send the query to a non-standard port on the server, instead of the default port 53. This option would be used to test a name server that has been configured to listen for queries on a non-standard port number.

-q name

The domain name to query. This is useful to distinguish the name from other arguments.

-r

Do not read options from ${HOME}/.digrc. This is useful for scripts that need predictable behaviour.

-t type

The resource record type to query. It can be any valid query type. If it is a resource record type supported in BIND 9, it can be given by the type mnemonic (such as “NS” or “AAAA”). The default query type is “A”, unless the -x option is supplied to indicate a reverse lookup. A zone transfer can be requested by specifying a type of AXFR. When an incremental zone transfer (IXFR) is required, set the type to ixfr=N. The incremental zone transfer will contain the changes made to the zone since the serial number in the zone’s SOA record was N.

All resource record types can be expressed as “TYPEnn”, where “nn” is the number of the type. If the resource record type is not supported in BIND 9, the result will be displayed as described in RFC 3597.

-u

Print query times in microseconds instead of milliseconds.

-v

Print the version number and exit.

-x addr

Simplified reverse lookups, for mapping addresses to names. The addr is an IPv4 address in dotted-decimal notation, or a colon-delimited IPv6 address. When the -x is used, there is no need to provide the name, class and type arguments. dig automatically performs a lookup for a name like 94.2.0.192.in-addr.arpa and sets the query type and class to PTR and IN respectively. IPv6 addresses are looked up using nibble format under the IP6.ARPA domain.

-y [hmac:]keyname:secret

Sign queries using TSIG with the given authentication key. keyname is the name of the key, and secret is the base64 encoded shared secret. hmac is the name of the key algorithm; valid choices are hmac-md5, hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, or hmac-sha512. If hmac is not specified, the default is hmac-md5 or if MD5 was disabled hmac-sha256.

Note

You should use the -k option and avoid the -y option, because with -y the shared secret is supplied as a command line argument in clear text. This may be visible in the output from ps1 or in a history file maintained by the user’s shell.

Query Options¶

dig provides a number of query options which affect the way in which lookups are made and the results displayed. Some of these set or reset flag bits in the query header, some determine which sections of the answer get printed, and others determine the timeout and retry strategies.

Each query option is identified by a keyword preceded by a plus sign (+). Some keywords set or reset an option. These may be preceded by the string no to negate the meaning of that keyword. Other keywords assign values to options like the timeout interval. They have the form +keyword=value. Keywords may be abbreviated, provided the abbreviation is unambiguous; for example, +cd is equivalent to +cdflag. The query options are:

+[no]aaflag

A synonym for +[no]aaonly.

+[no]aaonly

Sets the “aa” flag in the query.

+[no]additional

Display [do not display] the additional section of a reply. The default is to display it.

+[no]adflag

Set [do not set] the AD (authentic data) bit in the query. This requests the server to return whether all of the answer and authority sections have all been validated as secure according to the security policy of the server. AD=1 indicates that all records have been validated as secure and the answer is not from a OPT-OUT range. AD=0 indicate that some part of the answer was insecure or not validated. This bit is set by default.

+[no]all

Set or clear all display flags.

+[no]answer

Display [do not display] the answer section of a reply. The default is to display it.

+[no]authority

Display [do not display] the authority section of a reply. The default is to display it.

+[no]badcookie

Retry lookup with the new server cookie if a BADCOOKIE response is received.

+[no]besteffort

Attempt to display the contents of messages which are malformed. The default is to not display malformed answers.

+bufsize=B

Set the UDP message buffer size advertised using EDNS0 to B bytes. The maximum and minimum sizes of this buffer are 65535 and 0 respectively. Values outside this range are rounded up or down appropriately. Values other than zero will cause a EDNS query to be sent.

+[no]cdflag

Set [do not set] the CD (checking disabled) bit in the query. This requests the server to not perform DNSSEC validation of responses.

+[no]class

Display [do not display] the CLASS when printing the record.

+[no]cmd

Toggles the printing of the initial comment in the output, identifying the version of dig and the query options that have been applied. This option always has global effect; it cannot be set globally and then overridden on a per-lookup basis. The default is to print this comment.

+[no]comments

Toggles the display of some comment lines in the output, containing information about the packet header and OPT pseudosection, and the names of the response section. The default is to print these comments.

Other types of comments in the output are not affected by this option, but can be controlled using other command line switches. These include +[no]cmd, +[no]question, +[no]stats, and +[no]rrcomments.

+[no]cookie=####

Send a COOKIE EDNS option, with optional value. Replaying a COOKIE from a previous response will allow the server to identify a previous client. The default is +cookie.

+cookie is also set when +trace is set to better emulate the default queries from a nameserver.

+[no]crypto

Toggle the display of cryptographic fields in DNSSEC records. The contents of these field are unnecessary to debug most DNSSEC validation failures and removing them makes it easier to see the common failures. The default is to display the fields. When omitted they are replaced by the string “[omitted]” or in the DNSKEY case the key id is displayed as the replacement, e.g. “[ key id = value ]”.

+[no]defname

Deprecated, treated as a synonym for +[no]search

+[no]dnssec

Requests DNSSEC records be sent by setting the DNSSEC OK bit (DO) in the OPT record in the additional section of the query.

+domain=somename

Set the search list to contain the single domain somename, as if specified in a domain directive in /etc/resolv.conf, and enable search list processing as if the +search option were given.

+dscp=value

Set the DSCP code point to be used when sending the query. Valid DSCP code points are in the range [0..63]. By default no code point is explicitly set.

+[no]edns[=#]

Specify the EDNS version to query with. Valid values are 0 to 255. Setting the EDNS version will cause a EDNS query to be sent. +noedns clears the remembered EDNS version. EDNS is set to 0 by default.

+[no]ednsflags[=#]

Set the must-be-zero EDNS flags bits (Z bits) to the specified value. Decimal, hex and octal encodings are accepted. Setting a named flag (e.g. DO) will silently be ignored. By default, no Z bits are set.

+[no]ednsnegotiation

Enable / disable EDNS version negotiation. By default EDNS version negotiation is enabled.

+[no]ednsopt[=code[:value]]

Specify EDNS option with code point code and optionally payload of value as a hexadecimal string. code can be either an EDNS option name (for example, NSID or ECS), or an arbitrary numeric value. +noednsopt clears the EDNS options to be sent.

+[no]expire

Send an EDNS Expire option.

+[no]fail

Do not try the next server if you receive a SERVFAIL. The default is to not try the next server which is the reverse of normal stub resolver behavior.

+[no]header-only

Send a query with a DNS header without a question section. The default is to add a question section. The query type and query name are ignored when this is set.

+[no]identify

Show [or do not show] the IP address and port number that supplied the answer when the +short option is enabled. If short form answers are requested, the default is not to show the source address and port number of the server that provided the answer.

+[no]idnin

Process [do not process] IDN domain names on input. This requires IDN SUPPORT to have been enabled at compile time.

The default is to process IDN input when standard output is a tty. The IDN processing on input is disabled when dig output is redirected to files, pipes, and other non-tty file descriptors.

+[no]idnout

Convert [do not convert] puny code on output. This requires IDN SUPPORT to have been enabled at compile time.

The default is to process puny code on output when standard output is a tty. The puny code processing on output is disabled when dig output is redirected to files, pipes, and other non-tty file descriptors.

+[no]ignore

Ignore truncation in UDP responses instead of retrying with TCP. By default, TCP retries are performed.

+[no]keepalive

Send [or do not send] an EDNS Keepalive option.

+[no]keepopen

Keep the TCP socket open between queries and reuse it rather than creating a new TCP socket for each lookup. The default is +nokeepopen.

+[no]mapped

Allow mapped IPv4 over IPv6 addresses to be used. The default is +mapped.

+[no]multiline

Print records like the SOA records in a verbose multi-line format with human-readable comments. The default is to print each record on a single line, to facilitate machine parsing of the dig output.

+ndots=D

Set the number of dots that have to appear in name to D for it to be considered absolute. The default value is that defined using the ndots statement in /etc/resolv.conf, or 1 if no ndots statement is present. Names with fewer dots are interpreted as relative names and will be searched for in the domains listed in the search or domain directive in /etc/resolv.conf if +search is set.

+[no]nsid

Include an EDNS name server ID request when sending a query.

+[no]nssearch

When this option is set, dig attempts to find the authoritative name servers for the zone containing the name being looked up and display the SOA record that each name server has for the zone. Addresses of servers that that did not respond are also printed.

+[no]onesoa

Print only one (starting) SOA record when performing an AXFR. The default is to print both the starting and ending SOA records.

+[no]opcode=value

Set [restore] the DNS message opcode to the specified value. The default value is QUERY (0).

+padding=value

Pad the size of the query packet using the EDNS Padding option to blocks of value bytes. For example, +padding=32 would cause a 48-byte query to be padded to 64 bytes. The default block size is 0, which disables padding. The maximum is 512. Values are ordinarily expected to be powers of two, such as 128; however, this is not mandatory. Responses to padded queries may also be padded, but only if the query uses TCP or DNS COOKIE.

+[no]qr

Toggles the display of the query message as it is sent. By default, the query is not printed.

+[no]question

Toggles the display of the question section of a query when an answer is returned. The default is to print the question section as a comment.

+[no]raflag

Set [do not set] the RA (Recursion Available) bit in the query. The default is +noraflag. This bit should be ignored by the server for QUERY.

+[no]rdflag

A synonym for +[no]recurse.

+[no]recurse

Toggle the setting of the RD (recursion desired) bit in the query. This bit is set by default, which means dig normally sends recursive queries. Recursion is automatically disabled when the +nssearch or +trace query options are used.

+retry=T

Sets the number of times to retry UDP queries to server to T instead of the default, 2. Unlike +tries, this does not include the initial query.

+[no]rrcomments

Toggle the display of per-record comments in the output (for example, human-readable key information about DNSKEY records). The default is not to print record comments unless multiline mode is active.

+[no]search

Use [do not use] the search list defined by the searchlist or domain directive in resolv.conf (if any). The search list is not used by default.

‘ndots’ from resolv.conf (default 1) which may be overridden by +ndots determines if the name will be treated as relative or not and hence whether a search is eventually performed or not.

+[no]short

Provide a terse answer. The default is to print the answer in a verbose form. This option always has global effect; it cannot be set globally and then overridden on a per-lookup basis.

+[no]showsearch

Perform [do not perform] a search showing intermediate results.

+[no]sigchase

This feature is now obsolete and has been removed; use delv instead.

+split=W

Split long hex- or base64-formatted fields in resource records into chunks of W characters (where W is rounded up to the nearest multiple of 4). +nosplit or +split=0 causes fields not to be split at all. The default is 56 characters, or 44 characters when multiline mode is active.

+[no]stats

Toggles the printing of statistics: when the query was made, the size of the reply and so on. The default behavior is to print the query statistics as a comment after each lookup.

+[no]subnet=addr[/prefix-length]

Send (don’t send) an EDNS Client Subnet option with the specified IP address or network prefix.

dig +subnet=0.0.0.0/0, or simply dig +subnet=0 for short, sends an EDNS CLIENT-SUBNET option with an empty address and a source prefix-length of zero, which signals a resolver that the client’s address information must not be used when resolving this query.

+[no]tcflag

Set [do not set] the TC (TrunCation) bit in the query. The default is +notcflag. This bit should be ignored by the server for QUERY.

+[no]tcp

Use [do not use] TCP when querying name servers. The default behavior is to use UDP unless a type any or ixfr=N query is requested, in which case the default is TCP. AXFR queries always use TCP.

+timeout=T

Sets the timeout for a query to T seconds. The default timeout is 5 seconds. An attempt to set T to less than 1 will result in a query timeout of 1 second being applied.

+[no]topdown

This feature is related to dig +sigchase, which is obsolete and has been removed. Use delv instead.

+[no]trace

Toggle tracing of the delegation path from the root name servers for the name being looked up. Tracing is disabled by default. When tracing is enabled, dig makes iterative queries to resolve the name being looked up. It will follow referrals from the root servers, showing the answer from each server that was used to resolve the lookup.

If @server is also specified, it affects only the initial query for the root zone name servers.

+dnssec is also set when +trace is set to better emulate the default queries from a nameserver.

+tries=T

Sets the number of times to try UDP queries to server to T instead of the default, 3. If T is less than or equal to zero, the number of tries is silently rounded up to 1.

+trusted-key=####

Formerly specified trusted keys for use with dig +sigchase. This feature is now obsolete and has been removed; use delv instead.

+[no]ttlid

Display [do not display] the TTL when printing the record.

+[no]ttlunits

Display [do not display] the TTL in friendly human-readable time units of “s”, “m”, “h”, “d”, and “w”, representing seconds, minutes, hours, days and weeks. Implies +ttlid.

+[no]unexpected

Accept [do not accept] answers from unexpected sources. By default, dig won’t accept a reply from a source other than the one to which it sent the query.

+[no]unknownformat

Print all RDATA in unknown RR type presentation format (RFC 3597). The default is to print RDATA for known types in the type’s presentation format.

+[no]vc

Use [do not use] TCP when querying name servers. This alternate syntax to +[no]tcp is provided for backwards compatibility. The “vc” stands for “virtual circuit”.

+[no]yaml

Print the responses (and, if <option>+qr</option> is in use, also the outgoing queries) in a detailed YAML format.

+[no]zflag

Set [do not set] the last unassigned DNS header flag in a DNS query. This flag is off by default.

Multiple Queries¶

The BIND 9 implementation of dig supports specifying multiple queries on the command line (in addition to supporting the -f batch file option). Each of those queries can be supplied with its own set of flags, options and query options.

In this case, each query argument represent an individual query in the command-line syntax described above. Each consists of any of the standard options and flags, the name to be looked up, an optional query type and class and any query options that should be applied to that query.

A global set of query options, which should be applied to all queries, can also be supplied. These global query options must precede the first tuple of name, class, type, options, flags, and query options supplied on the command line. Any global query options (except +[no]cmd and +[no]short options) can be overridden by a query-specific set of query options. For example:

dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr

shows how dig could be used from the command line to make three lookups: an ANY query for www.isc.org, a reverse lookup of 127.0.0.1 and a query for the NS records of isc.org. A global query option of +qr is applied, so that dig shows the initial query it made for each lookup. The final query has a local query option of +noqr which means that dig will not print the initial query when it looks up the NS records for isc.org.

IDN Support¶

If dig has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. dig appropriately converts character encoding of domain name before sending a request to DNS server or displaying a reply from the server. If you’d like to turn off the IDN support for some reason, use parameters +noidnin and +noidnout or define the IDN_DISABLE environment variable.

Files¶

/etc/resolv.conf

${HOME}/.digrc

Bugs¶

There are probably too many query options.

nslookup - query Internet name servers interactively¶

Synopsis¶

nslookup [-option] [name | -] [server]

Description¶

Nslookup is a program to query Internet domain name servers. Nslookup has two modes: interactive and non-interactive. Interactive mode allows the user to query name servers for information about various hosts and domains or to print a list of hosts in a domain. Non-interactive mode is used to print just the name and requested information for a host or domain.

Arguments¶

Interactive mode is entered in the following cases:

when no arguments are given (the default name server will be used)
when the first argument is a hyphen (-) and the second argument is the host name or Internet address of a name server.

Non-interactive mode is used when the name or Internet address of the host to be looked up is given as the first argument. The optional second argument specifies the host name or address of a name server.

Options can also be specified on the command line if they precede the arguments and are prefixed with a hyphen. For example, to change the default query type to host information, and the initial timeout to 10 seconds, type:

nslookup -query=hinfo  -timeout=10

The -version option causes nslookup to print the version number and immediately exits.

Interactive Commands¶

host [server]

Look up information for host using the current default server or using server, if specified. If host is an Internet address and the query type is A or PTR, the name of the host is returned. If host is a name and does not have a trailing period, the search list is used to qualify the name.

To look up a host not in the current domain, append a period to the name.

server domain | lserver domain

Change the default server to domain; lserver uses the initial server to look up information about domain, while server uses the current default server. If an authoritative answer can’t be found, the names of servers that might have the answer are returned.

root

not implemented

finger

not implemented

ls

not implemented

view

not implemented

help

not implemented

?

not implemented

exit

Exits the program.

set keyword[=value]

This command is used to change state information that affects the lookups. Valid keywords are:

all

Prints the current values of the frequently used options to set. Information about the current default server and host is also printed.

class=value

Change the query class to one of:

IN: the Internet class
CH: the Chaos class
HS: the Hesiod class
ANY: wildcard

The class specifies the protocol group of the information.

(Default = IN; abbreviation = cl)

nodebug

Turn on or off the display of the full response packet and any intermediate response packets when searching.

(Default = nodebug; abbreviation = [no]deb)

nod2

Turn debugging mode on or off. This displays more about what nslookup is doing.

(Default = nod2)

domain=name

Sets the search list to name.

nosearch

If the lookup request contains at least one period but doesn’t end with a trailing period, append the domain names in the domain search list to the request until an answer is received.

(Default = search)

port=value

Change the default TCP/UDP name server port to value.

(Default = 53; abbreviation = po)

querytype=value | type=value

Change the type of the information query.

(Default = A and then AAAA; abbreviations = q, ty)

Note: It is only possible to specify one query type, only the default: behavior looks up both when an alternative is not specified.

norecurse

Tell the name server to query other servers if it does not have the information.

(Default = recurse; abbreviation = [no]rec)

ndots=number

Set the number of dots (label separators) in a domain that will disable searching. Absolute names always stop searching.

retry=number

Set the number of retries to number.

timeout=number

Change the initial timeout interval for waiting for a reply to number seconds.

novc

Always use a virtual circuit when sending requests to the server.

(Default = novc)

nofail

Try the next nameserver if a nameserver responds with SERVFAIL or a referral (nofail) or terminate query (fail) on such a response.

(Default = nofail)

Return Values¶

nslookup returns with an exit status of 1 if any query failed, and 0 otherwise.

IDN Support¶

If nslookup has been built with IDN (internationalized domain name) support, it can accept and display non-ASCII domain names. nslookup appropriately converts character encoding of domain name before sending a request to DNS server or displaying a reply from the server. If you’d like to turn off the IDN support for some reason, define the IDN_DISABLE environment variable. The IDN support is disabled if the variable is set when nslookup runs or when the standard output is not a tty.

Files¶

/etc/resolv.conf

named - Internet domain name server¶

Synopsis¶

named [ [-4] | [-6] ] [-c config-file] [-d debug-level] [-D string] [-E engine-name] [-f] [-g] [-L logfile] [-M option] [-m flag] [-n #cpus] [-p port] [-s] [-S #max-socks] [-t directory] [-U #listeners] [-u user] [-v] [-V] [-X lock-file] [-x cache-file]

Description¶

named is a Domain Name System (DNS) server, part of the BIND 9 distribution from ISC. For more information on the DNS, see RFC 1033, RFC 1034, and RFC 1035.

When invoked without arguments, named will read the default configuration file /etc/named.conf, read any initial data, and listen for queries.

Options¶

-4

Use IPv4 only even if the host machine is capable of IPv6. -4 and -6 are mutually exclusive.

-6

Use IPv6 only even if the host machine is capable of IPv4. -4 and -6 are mutually exclusive.

-c config-file

Use config-file as the configuration file instead of the default, /etc/named.conf. To ensure that reloading the configuration file continues to work after the server has changed its working directory due to to a possible directory option in the configuration file, config-file should be an absolute pathname.

-d debug-level

Set the daemon’s debug level to debug-level. Debugging traces from named become more verbose as the debug level increases.

-D string

Specifies a string that is used to identify a instance of named in a process listing. The contents of string are not examined.

-E engine-name

When applicable, specifies the hardware to use for cryptographic operations, such as a secure key store used for signing.

When BIND is built with OpenSSL PKCS#11 support, this defaults to the string “pkcs11”, which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (–enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via “–with-pkcs11”.

-f

Run the server in the foreground (i.e. do not daemonize).

-g

Run the server in the foreground and force all logging to stderr.

-L logfile

Log to the file logfile by default instead of the system log.

-M option

Sets the default memory context options. If set to external, this causes the internal memory manager to be bypassed in favor of system-provided memory allocation functions. If set to fill, blocks of memory will be filled with tag values when allocated or freed, to assist debugging of memory problems. (nofill disables this behavior, and is the default unless named has been compiled with developer options.)

-m flag

Turn on memory usage debugging flags. Possible flags are usage, trace, record, size, and mctx. These correspond to the ISC_MEM_DEBUGXXXX flags described in <isc/mem.h>.

-n #cpus

Create #cpus worker threads to take advantage of multiple CPUs. If not specified, named will try to determine the number of CPUs present and create one thread per CPU. If it is unable to determine the number of CPUs, a single worker thread will be created.

-p port

Listen for queries on port port. If not specified, the default is port 53.

-s

Write memory usage statistics to stdout on exit.

Note

This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.

-S #max-socks: Allow named to use up to #max-socks sockets. The default value is 21000 on systems built with default configuration options, and 4096 on systems built with “configure –with-tuning=small”.

Warning

This option should be unnecessary for the vast majority of users. The use of this option could even be harmful because the specified value may exceed the limitation of the underlying system API. It is therefore set only when the default configuration causes exhaustion of file descriptors and the operational environment is known to support the specified number of sockets. Note also that the actual maximum number is normally a little fewer than the specified value because named reserves some file descriptors for its internal use.

-t directory: Chroot to directory after processing the command line arguments, but before reading the configuration file.

Warning

This option should be used in conjunction with the -u option, as chrooting a process running as root doesn’t enhance security on most systems; the way chroot(2) is defined allows a process with root privileges to escape a chroot jail.

-U #listeners: Use #listeners worker threads to listen for incoming UDP packets on each address. If not specified, named will calculate a default value based on the number of detected CPUs: 1 for 1 CPU, and the number of detected CPUs minus one for machines with more than 1 CPU. This cannot be increased to a value higher than the number of CPUs. If -n has been set to a higher value than the number of detected CPUs, then -U may be increased as high as that value, but no higher. On Windows, the number of UDP listeners is hardwired to 1 and this option has no effect.
-u user: Setuid to user after completing privileged operations, such as creating sockets that listen on privileged ports.

Note

On Linux, named uses the kernel’s capability mechanism to drop all root privileges except the ability to bind(2) to a privileged port and set process resource limits. Unfortunately, this means that the -u option only works when named is run on kernel 2.2.18 or later, or kernel 2.3.99-pre3 or later, since previous kernels did not allow privileges to be retained after setuid(2).

-v: Report the version number and exit.
-V: Report the version number and build options, and exit.
-X lock-file: Acquire a lock on the specified file at runtime; this helps to prevent duplicate named instances from running simultaneously. Use of this option overrides the lock-file option in named.conf. If set to none, the lock file check is disabled.
-x cache-file: Load data from cache-file into the cache of the default view.

Warning

This option must not be used. It is only of interest to BIND 9 developers and may be removed or changed in a future release.

Signals¶

In routine operation, signals should not be used to control the nameserver; rndc should be used instead.

SIGHUP: Force a reload of the server.
SIGINT, SIGTERM: Shut down the server.

The result of sending any other signals to the server is undefined.

Configuration¶

The named configuration file is too complex to describe in detail here. A complete description is provided in the BIND 9 Administrator Reference Manual.

named inherits the umask (file creation mode mask) from the parent process. If files created by named, such as journal files, need to have custom permissions, the umask should be set explicitly in the script used to start the named process.

Files¶

/etc/named.conf: The default configuration file.
/var/run/named/named.pid: The default process-id file.

pkcs11-keygen - generate keys on a PKCS#11 device¶

Synopsis¶

pkcs11-keygen [-a algorithm] [-b keysize] [-e] [-i id] [-m module] [-P] [-p PIN] [-q] [-S] [-s slot] label

Description¶

pkcs11-keygen causes a PKCS#11 device to generate a new key pair with the given label (which must be unique) and with keysize bits of prime.

Arguments¶

-a algorithm: Specify the key algorithm class: Supported classes are RSA, DSA, DH, ECC and ECX. In addition to these strings, the algorithm can be specified as a DNSSEC signing algorithm that will be used with this key; for example, NSEC3RSASHA1 maps to RSA, ECDSAP256SHA256 maps to ECC, and ED25519 to ECX. The default class is “RSA”.
-b keysize: Create the key pair with keysize bits of prime. For ECC keys, the only valid values are 256 and 384, and the default is 256. For ECX keys, the only valid values are 256 and 456, and the default is 256.
-e: For RSA keys only, use a large exponent.
-i id: Create key objects with id. The id is either an unsigned short 2 byte or an unsigned long 4 byte number.
-m module: Specify the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-P: Set the new private key to be non-sensitive and extractable. The allows the private key data to be read from the PKCS#11 device. The default is for private keys to be sensitive and non-extractable.
-p PIN: Specify the PIN for the device. If no PIN is provided on the command line, pkcs11-keygen will prompt for it.
-q: Quiet mode: suppress unnecessary output.
-S: For Diffie-Hellman (DH) keys only, use a special prime of 768, 1024 or 1536 bit size and base (aka generator) 2. If not specified, bit size will default to 1024.
-s slot: Open the session with the given PKCS#11 slot. The default is slot 0.

pkcs11-tokens - list PKCS#11 available tokens¶

Synopsis¶

pkcs11-tokens [-m module] [-v]

Description¶

pkcs11-tokens lists the PKCS#11 available tokens with defaults from the slot/token scan performed at application initialization.

Arguments¶

-m module: Specify the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-v: Make the PKCS#11 libisc initialization verbose.

pkcs11-list - list PKCS#11 objects¶

pkcs11-list [-P] [-m module] [-s slot] [-i ID ] [-l label] [-p PIN]

Description¶

pkcs11-list lists the PKCS#11 objects with ID or label or by default all objects. The object class, label, and ID are displayed for all keys. For private or secret keys, the extractability attribute is also displayed, as either true, false, or never.

Arguments¶

-P: List only the public objects. (Note that on some PKCS#11 devices, all objects are private.)
-m module: Specify the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-s slot: Open the session with the given PKCS#11 slot. The default is slot 0.
-i ID: List only key objects with the given object ID.
-l label: List only key objects with the given label.
-p PIN: Specify the PIN for the device. If no PIN is provided on the command line, pkcs11-list will prompt for it.

Synopsis¶

pkcs11-destroy [-m module] [-s slot] [-i ID] [-l label] [-p PIN] [-w seconds]

Description¶

pkcs11-destroy destroys keys stored in a PKCS#11 device, identified by their ID or label.

Matching keys are displayed before being destroyed. By default, there is a five second delay to allow the user to interrupt the process before the destruction takes place.

Arguments¶

-m module: Specify the PKCS#11 provider module. This must be the full path to a shared library object implementing the PKCS#11 API for the device.
-s slot: Open the session with the given PKCS#11 slot. The default is slot 0.
-i ID: Destroy keys with the given object ID.
-l label: Destroy keys with the given label.
-p PIN: Specify the PIN for the device. If no PIN is provided on the command line, pkcs11-destroy will prompt for it.
-w seconds: Specify how long to pause before carrying out key destruction. The default is five seconds. If set to 0, destruction will be immediate.

named-checkconf - named configuration file syntax checking tool¶

Synopsis¶

named-checkconf [-chjlvz] [-p [-x ]] [-t directory] {filename}

Description¶

named-checkconf checks the syntax, but not the semantics, of a named configuration file. The file is parsed and checked for syntax errors, along with all files included by it. If no file is specified, /etc/named.conf is read by default.

Note: files that named reads in separate parser contexts, such as rndc.key and bind.keys, are not automatically read by named-checkconf. Configuration errors in these files may cause named to fail to run, even if named-checkconf was successful. named-checkconf can be run on these files explicitly, however.

Options¶

-h: Print the usage summary and exit.
-j: When loading a zonefile read the journal if it exists.
-l: List all the configured zones. Each line of output contains the zone name, class (e.g. IN), view, and type (e.g. master or slave).
-c: Check “core” configuration only. This suppresses the loading of plugin modules, and causes all parameters to plugin statements to be ignored.
-i: Ignore warnings on deprecated options.
-p: Print out the named.conf and included files in canonical form if no errors were detected. See also the -x option.
-t directory: Chroot to directory so that include directives in the configuration file are processed as if run by a similarly chrooted named.
-v: Print the version of the named-checkconf program and exit.
-x: When printing the configuration files in canonical form, obscure shared secrets by replacing them with strings of question marks (‘?’). This allows the contents of named.conf and related files to be shared MDASH for example, when submitting bug reports MDASH without compromising private data. This option cannot be used without -p.
-z: Perform a test load of all master zones found in named.conf.
filename: The name of the configuration file to be checked. If not specified, it defaults to /etc/named.conf.

Return Values¶

named-checkconf returns an exit status of 1 if errors were detected and 0 otherwise.

named-checkzone, named-compilezone - zone file validity checking or converting tool¶

Synopsis¶

named-checkzone [-d] [-h] [-j] [-q] [-v] [-c class] [-f format] [-F format] [-J filename] [-i mode] [-k mode] [-m mode] [-M mode] [-n mode] [-l ttl] [-L serial] [-o filename] [-r mode] [-s style] [-S mode] [-t directory] [-T mode] [-w directory] [-D] [-W mode] {zonename} {filename}

named-compilezone [-d] [-j] [-q] [-v] [-c class] [-C mode] [-f format] [-F format] [-J filename] [-i mode] [-k mode] [-m mode] [-n mode] [-l ttl] [-L serial] [-r mode] [-s style] [-t directory] [-T mode] [-w directory] [-D] [-W mode] {-o filename} {zonename} {filename}

Description¶

named-checkzone checks the syntax and integrity of a zone file. It performs the same checks as named does when loading a zone. This makes named-checkzone useful for checking zone files before configuring them into a name server.

named-compilezone is similar to named-checkzone, but it always dumps the zone contents to a specified file in a specified format. Additionally, it applies stricter check levels by default, since the dump output will be used as an actual zone file loaded by named. When manually specified otherwise, the check levels must at least be as strict as those specified in the named configuration file.

Options¶

-d

Enable debugging.

-h

Print the usage summary and exit.

-q

Quiet mode - exit code only.

-v

Print the version of the named-checkzone program and exit.

-j

When loading a zone file, read the journal if it exists. The journal file name is assumed to be the zone file name appended with the string .jnl.

-J filename

When loading the zone file read the journal from the given file, if it exists. (Implies -j.)

-c class

Specify the class of the zone. If not specified, “IN” is assumed.

-i mode

Perform post-load zone integrity checks. Possible modes are "full" (default), "full-sibling", "local", "local-sibling" and "none".

Mode "full" checks that MX records refer to A or AAAA record (both in-zone and out-of-zone hostnames). Mode "local" only checks MX records which refer to in-zone hostnames.

Mode "full" checks that SRV records refer to A or AAAA record (both in-zone and out-of-zone hostnames). Mode "local" only checks SRV records which refer to in-zone hostnames.

Mode "full" checks that delegation NS records refer to A or AAAA record (both in-zone and out-of-zone hostnames). It also checks that glue address records in the zone match those advertised by the child. Mode "local" only checks NS records which refer to in-zone hostnames or that some required glue exists, that is when the nameserver is in a child zone.

Mode "full-sibling" and "local-sibling" disable sibling glue checks but are otherwise the same as "full" and "local" respectively.

Mode "none" disables the checks.

-f format

Specify the format of the zone file. Possible formats are "text" (default), "raw", and "map".

-F format

Specify the format of the output file specified. For named-checkzone, this does not cause any effects unless it dumps the zone contents.

Possible formats are "text" (default), which is the standard textual representation of the zone, and "map", "raw", and "raw=N", which store the zone in a binary format for rapid loading by named. "raw=N" specifies the format version of the raw zone file: if N is 0, the raw file can be read by any version of named; if N is 1, the file can be read by release 9.9.0 or higher; the default is 1.

-k mode

Perform "check-names" checks with the specified failure mode. Possible modes are "fail" (default for named-compilezone), "warn" (default for named-checkzone) and "ignore".

-l ttl

Sets a maximum permissible TTL for the input file. Any record with a TTL higher than this value will cause the zone to be rejected. This is similar to using the max-zone-ttl option in named.conf.

-L serial

When compiling a zone to “raw” or “map” format, set the “source serial” value in the header to the specified serial number. (This is expected to be used primarily for testing purposes.)

-m mode

Specify whether MX records should be checked to see if they are addresses. Possible modes are "fail", "warn" (default) and "ignore".

-M mode

Check if a MX record refers to a CNAME. Possible modes are "fail", "warn" (default) and "ignore".

-n mode

Specify whether NS records should be checked to see if they are addresses. Possible modes are "fail" (default for named-compilezone), "warn" (default for named-checkzone) and "ignore".

-o filename

Write zone output to filename. If filename is - then write to standard out. This is mandatory for named-compilezone.

-r mode

Check for records that are treated as different by DNSSEC but are semantically equal in plain DNS. Possible modes are "fail", "warn" (default) and "ignore".

-s style

Specify the style of the dumped zone file. Possible styles are "full" (default) and "relative". The full format is most suitable for processing automatically by a separate script. On the other hand, the relative format is more human-readable and is thus suitable for editing by hand. For named-checkzone this does not cause any effects unless it dumps the zone contents. It also does not have any meaning if the output format is not text.

-S mode

Check if a SRV record refers to a CNAME. Possible modes are "fail", "warn" (default) and "ignore".

-t directory

Chroot to directory so that include directives in the configuration file are processed as if run by a similarly chrooted named.

-T mode

Check if Sender Policy Framework (SPF) records exist and issues a warning if an SPF-formatted TXT record is not also present. Possible modes are "warn" (default), "ignore".

-w directory

chdir to directory so that relative filenames in master file $INCLUDE directives work. This is similar to the directory clause in named.conf.

-D

Dump zone file in canonical format. This is always enabled for named-compilezone.

-W mode

Specify whether to check for non-terminal wildcards. Non-terminal wildcards are almost always the result of a failure to understand the wildcard matching algorithm (RFC 1034). Possible modes are "warn" (default) and "ignore".

zonename

The domain name of the zone being checked.

filename

The name of the zone file.

Return Values¶

named-checkzone returns an exit status of 1 if errors were detected and 0 otherwise.

Manual Pages¶

rndc.conf - rndc configuration file¶

Synopsis¶

Description¶

Example¶

Name Server Configuration¶

See Also¶

rndc - name server control utility¶

Synopsis¶

Description¶

Options¶

Commands¶

Limitations¶

See Also¶

nsec3hash - generate NSEC3 hash¶

Synopsis¶

Description¶

Arguments¶

See Also¶

dnstap-read - print dnstap data in human-readable form¶

Synopsis¶

Description¶

Options¶

See Also¶

named-nzd2nzf - convert an NZD database to NZF text format¶

Synopsis¶

Description¶

Arguments¶

See Also¶

named-journalprint - print zone journal in human-readable form¶

Synopsis¶

Description¶

See Also¶

mdig - DNS pipelined lookup utility¶

Synopsis¶

Description¶

Anywhere Options¶

Global Options¶

Local Options¶

See Also¶

named-rrchecker - syntax checker for individual DNS resource records¶

Synopsis¶

Description¶

See Also¶

arpaname - translate IP addresses to the corresponding ARPA names¶

Synopsis¶

Description¶

See Also¶

dnssec-revoke - set the REVOKED bit on a DNSSEC key¶

Synopsis¶

Description¶

Options¶

See Also¶

dnssec-cds - change DS records for a child zone based on CDS/CDNSKEY¶

Synopsis¶

Description¶

Options¶

Exit Status¶

Examples¶

See Also¶

dnssec-keygen: DNSSEC key generation tool¶

Synopsis¶

Description¶

Options¶

Timing Options¶

Generated Keys¶

Example¶

See Also¶

dnssec-keyfromlabel - DNSSEC key generation tool¶

Synopsis¶

Description¶

Options¶

Timing Options¶

Generated Key Files¶

See Also¶

dnssec-verify - DNSSEC zone verification tool¶

Synopsis¶

Description¶

Options¶

See Also¶