Hi list, I'm trying to setup access to several internal websites that use Integrated Windows Authentication in a Windows XP/7/2008 environment through Squid 3.1.12. I successfully setup Squid to authenticate users using Kerberos or NTLM. With Internet Explorer and Firefox, users successfully authenticate to squid and get access to all websites (those without Integrated Windows Authentication actually work fine). However, all websites using Integrated Windows Authentication respond with a 401.1 Access Denied error, as it seems the request reaches the web server without information about the user's credential. Accessing those websites directly, works fine. I still don't fully understand how Integrated Windows Authentication really works, but is anyone successfully using it through a proxy? Any hints or links to documentation on how it should work in detail? Thanks, Javier