"Unrelated Additional Info" from Windows 2000 Active Director y servers

[Barry Margolin]

In article <9pilbl$rff at pub3.rc.vix.com>, O'Neil,Kevin <oneil at oclc.org> wrote:
>Here's the dig:
>
>net-thing 37 /tftpboot: dig soa metka-t.oa.oclc.org
>
>; <<>> DiG 8.3 <<>> soa metka-t.oa.oclc.org 
>;; res options: init recurs defnam dnsrch
>;; got answer:
>;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4
>;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
>;; QUERY SECTION:
>;;      metka-t.oa.oclc.org, type = SOA, class = IN
>
>;; AUTHORITY SECTION:
>oa.oclc.org.            1H IN SOA       oa1-server.oa.oclc.org.
>administrator.oa.oclc.org. (
>                                        47625           ; serial
>                                        15M             ; refresh
>                                        10M             ; retry
>                                        1D              ; expiry
>                                        15M )           ; minimum
>
>
>;; ADDITIONAL SECTION:
>oa1-server.oa.oclc.org.  1H IN A  132.174.29.60
>
>;; Total query time: 7 msec
>;; FROM: net-thing to SERVER: default -- 132.174.47.100
>;; WHEN: Thu Oct  4 16:00:46 2001
>;; MSG SIZE  sent: 37  rcvd: 114

What BIND is warning about is that there's no requirement to include the A
record for the SOA MNAME in the Additional Records section.  I suspect that
Microsoft DNS does it for the benefit of dynamic update clients; since
updates should be sent to the master server, they would need to do that A
query right after the SOA query (this is the same reason that related A
records are returned in MX or NS queries).

>I don't think that it's something to be concerned with.  And there doesn't
>seem to be anything to be done about it.

I suspect the reason for the warning is that inappropriate additional info
can be a source of cache poisoning.  I presume that the warning implies
that the unrelated records are being ignored, so the server complaining is
safe.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Woburn, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
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