Slow DNS lookup in Firefox with Karmic - resolved

[pokerfan]

This had been bugging me for the last couple of weeks. At first I thought it might have been my router as it has been known to behave like this at times. Anyway, I found this to be a large enough annoyance to list here just in case anyone else is having a similar issue.

The problem was that it was taking ages to open a web page. By ages, I mean anywhere from 20 seconds to over a minute or so. Once opened, everything would run pretty much at normal speeds but the initial delay was a major annoyance. Last night I decided to investigate further and found this:

https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/417757">all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups

In Karmic, DNS lookups take a very long time with some routers, because glibc's DNS resolver tries to do IPv6 (AAAA) lookups even if there are no (non-loopback) IPv6 interfaces configured. Routers which do not repond to this cause the lookup to take 20 seconds (until the IPv6 query times out).

The workaround for Firefox is to go into about:config and change the value for "network.dns.disableIPv6" from 'false' to 'true.'

Worked for me.

[RoyGBiv]

1. SuSE 11.1 had that problem too ...

I understand, in theory, why the IPv6 lookups happening, but it seems to me some way should exist to have them not activate if no interfaces for them exist. I may be talking out my hind quarters since I understand very little about all this at the moment, but it just seems logical.

The fix in SuSE was the same as what you found. That seems to be the accepted workaround.

[struggle4progress]

2. OS X made the same mistake a year and a half ago: Safari defaulted to the new standard

and would retry multiple times before reverting to the old standard

[pokerfan]

3. One advantage to open source

is that there's no corporate incentive to hide bugs and pretend that problems don't exist.

As Neal Stephenson wrote in 'In the Beginning,' "Joint stock corporations are wonderful inventions that have given us many excellent goods and services. They are good at many things. Admitting failure is not one of them. Hell, they can't even admit minor shortcomings. <...> When something goes wrong with Linux, the error is noticed and loudly discussed right away. Anyone with the requisite technical knowledge can go straight to the source code and point out the source of the error, which is then rapidly fixed by whichever hacker has carved out responsibility for that particular program."

http://en.wikipedia.org/wiki/In_the_Beginning..._was_the_Command_Line

[struggle4progress]

4. I already convinced of the advantages of open source. I have vista, osx, and linux

installations