pub enum OptRcode {
Show 14 variants
NoError,
FormErr,
ServFail,
NXDomain,
NotImp,
Refused,
YXDomain,
YXRRSet,
NXRRSet,
NotAuth,
NotZone,
BadVers,
BadCookie,
Int(u16),
}
Expand description
Extended DNS Response Codes for OPT records.
Originally, the response code of embedded in the header of each DNS message was four bits long. This code, defined in [RFC 1035], is represented by the Rcode type. The extension mechanism for DNS initially defined in RFC 2671 and updated by RFC 6891 added eight more bits to be stored in the OPT pseudo-resource record. This type represents the complete 12 bit extended response code.
There is a third, 16 bit wide response code for transaction
authentication (TSIG) defined in RFC 2845 and represented by the
TsigRcode
type. The code mostly shares the same name space except
for an unfortunate collision in between the BADVERS and BADSIG values.
Because of this, we decided to have separate types.
The values for all three response code types are defined in the IANA DNS RCODEs registry. This type is complete as of 2019-01-28.
Variants§
NoError
FormErr
ServFail
Server failure.
The name server was unable to process this query due to a problem with the name server.
Defined in RFC 1035.
NXDomain
Name error.
The domain name given in the query does not exist at the name server.
Defined in RFC 1035.
NotImp
Refused
Query refused.
The name server refused to perform the operation requested by the query for policy reasons.
Defined in RFC 1035.
YXDomain
Name exists when it should not.
Returned for an UPDATE query when a domain requested to not exist does in fact exist.
Returned when resolving a DNAME redirection when the resulting name exceeds the length of 255 octets.
Defined in RFC 2136 for the UPDATE query and RFC 6672 for DNAME redirection.
YXRRSet
RR set exists when it should not.
Returned for an UPDATE query when an RRset requested to not exist does in fact exist.
Defined in RFC 2136.
NXRRSet
RR set that should exist does not.
Returned for an UPDATE query when an RRset requested to exist does not.
Defined in RFC 2136.
NotAuth
Server not authoritative for zone or client not authorized.
Returned for an UPDATE query when the server is not an authoritative name server for the requested domain.
Returned for queries using TSIG when authorisation failed.
NotZone
Name not contained in zone.
A name used in the prerequisite or update section is not within the zone given in the zone section.
Defined in RFC 2136.
BadVers
Bad OPT version.
A name server does not implement the EDNS version requested in the OPT record.
Defined in RFC 6891.
BadCookie
Bad or missing server cookie.
The request contained a COOKIE option either without a server cookie or with a server cookie that did not validate.
Defined in RFC 7873.
Int(u16)
A raw, integer rcode value.
When converting to a 12 bit code, the upper four bits are simply ignored.