6. Message Header Response Codes

This section describes the response codes that can be returned in the RCODE field of the UPDATE response message.

NOERROR (0)

No error condition. The update was successful and all prerequisites were met.

FORMERR (1)

The name server was unable to interpret the request due to a format error. This can occur for various reasons, such as:

The Zone Section does not contain exactly one RR
The ZTYPE is not SOA
A prerequisite RR has an invalid CLASS/TYPE/RDATA combination
An update RR has an invalid CLASS/TYPE/RDATA combination
TTL is non-zero where it should be zero

SERVFAIL (2)

The name server encountered an internal failure while processing this request. Examples include:

Operating system errors (out of memory, disk full)
Hardware errors in persistent storage
Forwarding timeout when acting as a forwarder
Inability to undo a partially applied update after encountering an error

NXDOMAIN (3)

Some name that ought to exist, does not exist. This response code is used when a prerequisite condition checking for the existence of a name (CLASS=ANY, TYPE=ANY) is not satisfied.

NOTIMP (4)

The name server does not support the specified Opcode. This response is returned if the server does not implement the UPDATE opcode (value 5).

REFUSED (5)

The name server refuses to perform the specified operation for policy or security reasons. This can occur when:

The requestor does not have permission to perform the update
Security policy prohibits the requested update
The server is configured to reject all dynamic updates

YXDOMAIN (6)

Some name that ought not to exist, does exist. This response code is used when a prerequisite condition checking for the non-existence of a name (CLASS=NONE, TYPE=ANY) is not satisfied.

YXRRSET (7)

Some RRset that ought not to exist, does exist. This response code is used when a prerequisite condition checking for the non-existence of an RRset (CLASS=NONE, TYPE=specific) is not satisfied.

NXRRSET (8)

Some RRset that ought to exist, does not exist. This response code is used when:

A prerequisite condition checking for the existence of an RRset (CLASS=ANY, TYPE=specific) is not satisfied
A prerequisite condition checking for specific RR values (CLASS=zone) is not satisfied

NOTAUTH (9)

The server is not authoritative for the zone named in the Zone Section. The requestor should try a different server that is authoritative for the zone.

NOTZONE (10)

A name used in the Prerequisite or Update Section is not within the zone denoted by the Zone Section. This indicates an error in the UPDATE request, as all names in prerequisites and updates must be within the zone being updated.