Subject: Re: Unexpected AAAA queries
To: Thomas Seeger <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-net
Date: 07/08/2003 16:19:07
> While using NetBSD on an i386 machine I experience large delays in
> http/ftp/etc. connections:  [...tcpdump showing AAAA queries...]

> Pings are really fine:

This is no surprise; ping is strictly IPv4 only.  (There is a v6
analog, but it's a separate program, called ping6.) Apparently ping is
smart enough to do a v4-only lookup.

> The AAAA queries seem to be ipv6 related (?).

Yes; they are the v6 analog of v4's A records.  (Well, the
currently-used one.  There are also A6 records, but they aren't in live
use.)  The resolver library is trying to do IPv6 lookups.  (It doesn't
realize, at this point, that it can't do v6 connections, and indeed,
I'm not sure it should; it's perfectly reasonable to do a v6 address
lookup on a v4-only host.)

> Any hints to get rid of those AAAA queries?

Why?  I'd be more inclined to address the question of why they're going
unanswered.  What DNS server are you using?

If you really want to, you can probably rebuild the resolver libraries
without v6 support without too much trouble, though admittedly it's not
something I've ever tried.  It surely would be easy to kludge in a fast
"fake" failure for AAAA queries....

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