This post was made due to the frequency that this query comes up.

Firefox on some systems can sometimes have an issue in that it will not allow you to browse the web. However, using konqueror or an alternative browser seems to work fine, shows that it's not a network configuration issue.

It is however, a configuration issue within Firefox, and the way to resolve it is as follows.

1. Click in your url bar, and type "about:config" without the quotes.
2. In the Filter field type "ipv6" without the quotes.
3. The entry "network.dns.disableIPv6 should appear set as "false".
4. Double-click this entry, to set it to "true".

The browsing problem should now be resolved.

yupp., that fixed a problem that was driving me crazy.
I will drink a beer to honor you
Thank you

As an FYI, the item Ian refers to, is also present in the SeaMonkey suite and is also set to false by default.

Ubuntu had this problem and recent repositories of firefox include a ubuntu plugin that does this as well as a few other tweaks by default. I don't find that in the firefox addons though. Any thoughts?

This really isn't something that you should need a plugin for, as it's a configuration change, not a new feature. Chances are the "plugin" that Ubuntu includes is either just their changes to the configuration or some internal piece. Though the code is probably download-able from their repositories, I don't know where...

Firefox plugins are installed locally, at the user's profile, and so it's utterly unlikely that they can surpass the ipv6 issue mentioned by ianw1974 (which is a system-wide issue, and impossible to bypass by just installing a browser plugin).