Bug#435646: libc6: resolver considers IPv6 enabled when any IPv6 address is configured
Package: libc6
Version: 2.6-5
Severity: important
Tags: patch
Hi,
Tolleff fog Heen has written a patch for the resolver, so that it does
not start performing (or waiting for) AAAA lookups unless a globally
scoped IPv6 address is present on some interface.
Since Debian enables IPv6 by default, most users will have a system with
an IPv6 address on the loopback interface (as well as a link-local
address on each other interface) which will cause the current code to
commence lookups for AAAA records, only falling back to requesting A
records when these fail or timeout.
The patch here:
http://err.no/patches/glibc-only-lookup-ipv6-if-it-makes-sense.diff
seems to take a reasonable approach, since it will not be possible to
connect to IPv6 addresses without a globally scoped address (plus
routing :-) in any case.
This is an important issue because some users are so inconvenienced as
to be behind broken DNS infrastructure which ignores AAAA requests,
resulting in frequent timeouts with much confusion and frustration.
Thanks,
Andrew McMillan.
-- System Information:
Debian Release: lenny/sid
APT prefers unstable
APT policy: (690, 'unstable')
Architecture: i386 (i686)
Kernel: Linux 2.6.22.1-hippy (SMP w/2 CPU cores)
Locale: LANG=en_NZ.UTF-8, LC_CTYPE=POSIX (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/bash
Versions of packages libc6 depends on:
ii libgcc1 1:4.2-20070712-1 GCC support library
libc6 recommends no packages.
-- no debconf information
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