why do we see: "Opcode 6 not implemented"

[Jim Reid]

>>>>> "Jim" == Jim Reid <jim at rfc1035.com> writes:

    Jim> The source port number on the system sending these weird
    Jim> packets (474) might identify what's actually sending them.

Oops! Now I'm responding to my own postings. The source port number in
Danny's logs for those queries was actually 464, not 474. That is
assigned to kpasswd, some Kerberos V5 thing.

According to IANA (http://www.iana.org/assignments/dns-parameters)
opcodes 6-15 are "available for assignment".