Bug#557003: libc6: DNS queries are extremely slowed by ipv6
Package: libc6
Version: 2.10.1-7
Severity: important
When using Firefox, Google Chrome, Opera, Synaptic and other applications which use DNS, I always have to wait a long time (2 to 10 seconds) for a host to resolve (i.e. messages like "Resolving host", "Looking up http://whatever";, etc).
I always thought that this was a problem of my internet connection.
I could never track the origin of it until finally like 2 hours ago I stumbled across this:
https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/417757
To test if I had this problem, I opened up Firefox and got to about:config, entered ipv6 and set "network.dns.disableIPv6" to false. Immediately, every DNS query was extremely fast and browsing was up to par to my high speed internet connection.
To do a definite test, I added "ipv6_disable=1" to my kernel command line and after that all the applications above were having much faster DNS queries.
This is a rather serious bug that I have been experiencing ever since upgrading to testing (right after lenny's release), and always blamed on my ISP/wireless connection/configuration/etc, while finding it strange that every Mac or Windows PC near me using the same connection appeared to be much faster on DNS queries.
I guess there must be much more users affected by this and like me, they have no clue why.
It may be caused by a recent version of libc6, because the bug above is marked as "karmic regression" (the latest ubuntu is the karmic one, 9.10) and a friend of mine who is using lenny doesn't appear to have the same problem.
Pardon me if this as already been reported, I searched around but could not find a Debian version of this bug.
-- System Information:
Debian Release: squeeze/sid
APT prefers testing-proposed-updates
APT policy: (500, 'testing-proposed-updates'), (500, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.31.6 (SMP w/2 CPU cores; PREEMPT)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Versions of packages libc6 depends on:
ii libc-bin 2.10.1-7 GNU C Library: Binaries
ii libgcc1 1:4.4.1-4 GCC support library
Versions of packages libc6 recommends:
ii libc6-i686 2.10.1-7 GNU C Library: Shared libraries [i
Versions of packages libc6 suggests:
ii debconf [debconf-2.0] 1.5.28 Debian configuration management sy
pn glibc-doc <none> (no description available)
ii locales 2.10.1-7 GNU C Library: National Language (
-- debconf information excluded
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