dig response header

stuff returned in the dig header:

  • opcode: the requested operation

  • id: the 16-bit (0 to 65535) message ID supplied by the requester, and returned by the server, that identifies the transaction.

  • flags: one or more of:

    • qr (query response): a response to a query

    • aa (authoritative answer): set if the response was received from a zone master or slave.

    • tc: (truncation): length greater than permitted, set on all truncated messages except the last one.

    • rd (recursion desired): set in a query and copied into the response if recursion is available.

    • ra (recursion available): recursive query support is available.

    • ad (authenticated data), dnssec only: the data was reliably authenticated.

    • cd (checking disabled), dnssec only: disables checking at the server.

  • status response codes:

    • 0 = NOERR: no error.

    • 1 = FORMERR: format error- server was unable to interpret the query.

    • 2 = SERVFAIL: name server problem or lack of information. sometimes returned meaning REFUSED.

    • 3= NXDOMAIN Name does not exist: meaningful only from an authoritative name server.

    • 4 = NOTIMPL: not implemented.

    • 5 = REFUSED: usually due to policy e.g., a zone transfer request.