Understanding cause of DNS format error (FORMERR)
Sam.Wilson at ed.ac.uk
Mon Jun 25 15:21:07 UTC 2012
In article <mailman.1121.1340625284.63724.bind-users at lists.isc.org>,
Tony Finch <dot at dotat.at> wrote:
> It looks to me like this is an EDNS bug. ...
There's some kind of delegation bug as well. If I query
dns1[0-3].one.microsoft.com for SOA and NS for
partners.extranet.microsoft.com you get sensible answers though the
origin host is different for each server queried and those origins are
If I query dns1[0-3].one.microsoft.com for
vlasext.partners.extranet.microsoft.com/IN/A I get answers with no AA
bit set and a decreasing TTL as if the data were cached. It does not
appear that vlasext.partners.extranet.microsoft.com is delegated itself
so it's not cached answers from a child zone. The authority for
zero-answer responses such as
vlasext.partners.extranet.microsoft.com/IN/AAAA is the SOA for
It's all rather horrible.
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