resolver behaviour regarding searchlist and A/AAAA query replies

Jan Gyselinck freebsd-stable at
Thu May 4 22:03:30 UTC 2006


I was debugging some connection lag and I encountered some query
behavior which seems unnecessairy in my eyes.  The system in
question is running one of the FreeBSD 6.1 prereleases, I've not
verified this on any other version yet.

The queries I see are these:

22:15:29.657232 IP >  54355+ A? (37)
22:15:29.658189 IP >  46066+ AAAA? (37)
22:15:29.659407 IP >  54355 1/13/1 A (280)
22:15:29.659674 IP >  46066 0/1/0 (96)
22:15:29.660514 IP >  46067+ AAAA? (48)
22:15:29.661438 IP >  46067 NXDomain* 0/1/0 (99)
22:15:29.661847 IP >  46068+ AAAA? (55)
22:15:29.662720 IP >  46068 NXDomain* 0/1/0 (106)

So it sends out A and AAAA queries, so far so good.  It gets an answer
for the A record query, however the AAAA query retuns an empty answer.
What I find strange though, is the fact it's now applying the searchlist
to get an answer on the AAAA query.  Other than the fact this could
potentially give unpredictable results in specific situations, I find
this rather illogical.  Since one of the queries (A or AAAA) succeeded
we _know_ the host in question exists (and the searchlist is there to
make non-fqdn queries work for 'local' hosts, by applying the searchlist
if the host does not seem to exist).  So, in short, isn't this a bug?


Jan Gyselinck

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