On Thu, Apr 25, 2013 at 10:50 PM, Jürgen Obermeyer <squid@xxxxxxxx> wrote: > > My main idea is to try kerberos first, and if it fails, use basic > authentication. I don't understand why this works fine with Firefox, but not > with IE. Based on what you wrote, I think the authentication that is working for you is not negotiate, but basic. If I were you I would sniff some traffic to see what is really going on there.