Each served zone can have "metadata". Such metadata determines how this zone behaves in certain circumstances.

For the BIND backend, this information is either stored in the :ref:`setting-bind-dnssec-db` or the hybrid database, depending on your settings.

For the implementation in non-sql backends, please review your backend's documentation.

Apart from raw SQL statements, setting domain metadata can be done with pdnsutil set-meta and retrieving metadata is done with pdnsutil get-meta.

The following options can only be read (not written to) via the HTTP API metadata endpoint.

• API-RECTIFY
• AXFR-MASTER-TSIG
• LUA-AXFR-SCRIPT
• NSEC3NARROW
• NSEC3PARAM
• PRESIGNED
• TSIG-ALLOW-AXFR

The option SOA-EDIT-API can not be written or read via the HTTP API metadata endpoint.

Per-zone AXFR ACLs can be stored in the domainmetadata table.

Each ACL specifies one subnet (v4 or v6), or the magical value 'AUTO-NS' that tries to allow all potential slaves in.

Example:

pdnsutil set-meta powerdns.org ALLOW-AXFR-FROM AUTO-NS 2001:db8::/48

Each ACL has its own row in the database:

sql> select id from domains where name='example.com';
7
sql> insert into domainmetadata (domain_id, kind, content) values (7,'ALLOW-AXFR-FROM','AUTO-NS');
sql> insert into domainmetadata (domain_id, kind, content) values (7,'ALLOW-AXFR-FROM','2001:db8::/48');

To disallow all IP's, except those explicitly allowed by domainmetadata records, add allow-axfr-ips= to pdns.conf.

.. versionadded:: 4.1.0

This metadata item controls whether or not a zone is fully rectified on changes to the contents of a zone made through the :doc:`API <http-api/index>`.

When the API-RECTIFY value is "1", the zone will be rectified on changes. Any other other value means that it will not be rectified. If this is not set at all, rectifying of the zone depends on the config variable :ref:`setting-default-api-rectify`.

The IP address to use as a source address for sending AXFR and IXFR requests.

See the documentation on :ref:`Dynamic DNS update <dnsupdate-metadata>`.

When notifying this domain, also notify this nameserver (can occur multiple times). The nameserver may have contain an optional port number. e.g.:

pdnsutil set-meta powerdns.org ALSO-NOTIFY 192.0.2.1:5300
pdnsutil set-meta powerdns.org ALLOW-AXFR-FROM 2001:db8:53::1

Or in SQL:

insert into domainmetadata (domain_id, kind, content) values (7,'ALSO-NOTIFY','192.0.2.1:5300');
insert into domainmetadata (domain_id, kind, content) values (7,'ALLOW-AXFR-FROM','2001:db8:53::1');

Use this named TSIG key to retrieve this zone from its master, see :ref:`tsig-provision-signed-notify-axfr`.

Allow this GSS principal to perform AXFR retrieval. Most commonly it is host/something@REALM, DNS/something@REALM or user@REALM. (See :ref:`tsig-gss-tsig`).

Use this principal for accepting GSS context. (See :ref:`tsig-gss-tsig`).

If set to 1, attempt IXFR when retrieving zone updates. Otherwise IXFR is not attempted.

Script to be used to edit incoming AXFRs, see :ref:`modes-of-operation-axfrfilter`. This value will override the :ref:`setting-lua-axfr-script` setting. Use 'NONE' to remove a global script.

Set to "1" to tell PowerDNS this zone operates in NSEC3 'narrow' mode. See set-nsec3 for :doc:`pdnsutil <dnssec/pdnsutil>`.

NSEC3 parameters of a DNSSEC zone. Will be used to synthesize the NSEC3PARAM record. If present, NSEC3 is used, if not present, zones default to NSEC. See set-nsec3 in :doc:`pdnsutil <dnssec/pdnsutil>`. Example content: "1 0 1 ab".

This zone carries DNSSEC RRSIGs (signatures), and is presigned. PowerDNS sets this flag automatically upon incoming zone transfers (AXFR) if it detects DNSSEC records in the zone. However, if you import a presigned zone using zone2sql or pdnsutil load-zone you must explicitly set the zone to be PRESIGNED. Note that PowerDNS will not be able to correctly serve the zone if the imported data is bogus or incomplete. Also see set-presigned in :doc:`pdnsutil <dnssec/pdnsutil>`.

If a zone is presigned, the content of the metadata must be "1" (without the quotes). Any other value will not signal presignedness.

Whether to publish CDNSKEY and/or CDS recording defined in RFC 7344.

To publish CDNSKEY records of the KSKs for the zone, set PUBLISH-CDNSKEY to 1.

To publish CDS records for the KSKs in the zone, set PUBLISH-CDS to a comma- separated list of signature algorithm numbers.

This metadata can also be set using the :doc:`pdnsutil <dnssec/pdnsutil>` commands set-publish-cdnskey and set-publish-cds. For an example for an RFC 7344 key rollover, see the :doc:`guides/kskrollcdnskey`.

Global defaults for these values can be set via :ref:`setting-default-publish-cdnskey` and :ref:`setting-default-publish-cds`.

.. versionadded:: 4.3.0

If set to 1, will make PowerDNS renotify the slaves after an AXFR is received from a master. Any other value means that no renotifies are done. If not set at all, action will depend on the :ref:`setting-slave-renotify` setting.

When serving this zone, modify the SOA serial number in one of several ways. Mostly useful to get slaves to re-transfer a zone regularly to get fresh RRSIGs. See the :ref:`DNSSEC documentation <soa-edit-ensure-signature-freshness-on-slaves>` for more information.

On changes to the contents of a zone made through the :doc:`API <http-api/index>`, the SOA record will be edited according to the SOA-EDIT-API rules. These rules are the same as the :ref:`SOA-EDIT-DNSUPDATE <dnsupdate-soa-serial-updates>` rules. If not set during zone creation, a SOA-EDIT-API metadata record is created and set to DEFAULT. If this record is removed from the backend, the default behaviour is to not do any SOA editing based on this setting. This is different from setting DEFAULT.

Allow these named TSIG keys to AXFR this zone, see :ref:`tsig-provision-signed-notify-axfr`.

This setting allows you to set the TSIG key required to do an :doc:`dnsupdate`. If :ref:`GSS-TSIG <tsig-gss-tsig>` is enabled, you can put kerberos principals here as well.

Through the API and on the pdnsutil set-meta commandline, metadata unused by PowerDNS can be added. It is mandatory to prefix this extra metadata with "X-" and the name of the external application; the API will only allow this metadata if it starts with "X-".