How to correctly configure IE proxy settings?

Question

Our Admin has setup a squid proxy. On the my linux laptop, when I use firefox, it prompts me for my user name and password and the credentials are accepted. On windows, using IE :

1. I fill in the connexion dialog
2. I hit return
3. The dialog appears again, apparently because the credentials were rejected, but this time my user name has been modified like so : 192.168.20.1\user_name

Some have told me that Internet Explorer alters the user name field before sending it to the proxy, resulting in a denial of access.

Is there anything I can do to make it work ?

Answer 1

I suspect he's configured it to default to authenticate against windows domain accounts?

Try typing in your domain name in place of the IP address, e.g. where it says 192.168.20.1\user_name try typing your domain name at the start so it looks like this domain_name\user_name

Answer 2

MS says you may have to disable automatic proxy caching in IE via a registry change (MS Support article).