Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm experiencing strange problems with my Kubuntu 9.10 when doing DNS requests from various applications. The requests are extremely slow, so loading any pages in Firefox or Konqueror, doing package installations in Kpackagemanager and other apps is really painful, while for example Opera doesnt have any problems, and ping is normally fast as well for DNS pings.

I checked the proxy settings of both the used applications as well as of the general system and there are none, so to me it doesn't seem as there was something inbetween..

Does anybody have an idea on what to check for possible problem sources or how to solve this ? I'm behind a DSL home router which does the DHCP (and works well with my other computer).

Any kind of advice would be really helpful.

Edit: It seems to be some kind of IPv6 problem, as I could get it to work by disabling IPv6 explicitly in Firefox. Is there a general solution to this ?

share|improve this question

Check the answers to my question here. Even though that was on 9.04 it may help you with 9.10.

share|improve this answer

kubuntu karmik have a problem with ipv6, disable this

On firefox with about:config and set network.dns.disableIPv6 to false, later it works fine and fast.

On all kubuntu, edit /etc/default/grub and ad or modify this line for GRUB_CMDLINE_LINUX="ipv6.disable=1". Later run sudo update-grub and restart your computer


share|improve this answer
Very bad advise to disable IPv6 less than two years before the end of IPv4 addresses... – bortzmeyer Mar 12 '10 at 8:13
... There is no free porn or anything over ipv6. :) After 2 years, after 4 releases, he can start to worry about his IP. In my opinion, good advice. I'd go with this. (I'm using Win7 on desktop, and disable IPv6 always. Why would I need it when my ISP won't give me an address? ...Nor the homepages provide one.) – Shiki Jun 26 '10 at 12:00

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .