Painless NTLM authentication in Firefox

I've used Firefox heavily at work ever since they built NTLM authentication in, but have always been rather annoyed at how limited it is compared to the support built into IE. With IE there is no difference between accessing an intranet site that requires NTLM, and one that requires no authentication, assuming you're already logged into the network on your machine. Firefox on the other hand, would bring up its authentication dialog for each site, prompting for a username and password. Although allowing Firefox to save the password helped reduce the trouble to simply hitting Enter whenever such a box appeared, it was still annoying, and worse yet, slowed access to these servers.

After being notified by a server admin here that i was causing frequent authentication errors to show up in the logs, i decided it was time to investigate this problem further. Fortunately, a quick Google search brought me several hints at a solution, which was soon put in place.

The fix

1. In Firefox, type about:config into the address bar and hit enter. You should see a huge list of configuration properties.
2. Find the setting named network.automatic-ntlm-auth.trusted-uris (the easiest way to do this is to type that into the filter box at top).
3. Double-click this line, and enter the names of all servers for which NTLM is desired, separated by commas. Then press ‘OK’ to confirm.
4. Open the options dialog (Tools->Options menu), and on the General page press the Connection Settings button to get the proxy configuration dialog:
5. Make sure the correct proxy server is configured, and that the same list of servers are listed in the No Proxy for: entryfield as were set in step #3.
6. Done.

Result? No more slow access, no more authentication errors, no more clearing the list of saved passwords when i change my network password (or worse yet, having to call support and have my password reset because i forgot to do this...)