Mark Andrews wrote: > > Martin Rex writes: > > Mark Andrews wrote: > > > > > > "John Levine" writes: > > > > > > > > In case it wasn't clear, this is an authoritative server. > > > > If this is about permitted RCODEs here > > > > http://tools.ietf.org/html/rfc1035#section-4.1.1 > > > > then an RCODE of 4 in the response looks like a perfectly valid response > > for a DNS Server to a query, authoritative or not is irrelevant, and > > if any client chokes on such an answer, it is likely the client that > > is broken. > > No, its about what should be generated. NOTIMP != NOERROR no data. Maybe you believe that NOTIMP should be limited to unsupported OPCODES only? But that is definitely not what the spec says. Generating RCODE 4 (NOTIMP) seems _perfectly_ permissible for a DNS server when responding to a query for an QCLASS or QTYPE that the server does not implement. 4 Not Implemented - The name server does not support the requested kind of query. 1034&1035 are both at document maturity level "Full Standard", 1034 says: 3.7.1. Standard queries A standard query specifies a target domain name (QNAME), query type (QTYPE), and query class (QCLASS) and asks for RRs which match. This type of query makes up such a vast majority of DNS queries that we use the term "query" to mean standard query unless otherwise specified. The QTYPE and QCLASS fields are each 16 bits long, and are a superset of defined types and classes. 1035 says: RCODE Response code - this 4 bit field is set as part of responses. The values have the following interpretation: 0 No error condition 1 Format error - The name server was unable to interpret the query. 2 Server failure - The name server was unable to process this query due to a problem with the name server. 3 Name Error - Meaningful only for responses from an authoritative name server, this code signifies that the domain name referenced in the query does not exist. 4 Not Implemented - The name server does not support the requested kind of query. 5 Refused - The name server refuses to perform the specified operation for policy reasons. For example, a name server may not wish to provide the information to the particular requester, or a name server may not wish to perform a particular operation (e.g., zone transfer) for particular data. 6-15 Reserved for future use. -Martin _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf