I recently rebuilt our main proxy server at work and decided to get some sort of authentication mechanism installed. With Squid version 2.5 and above they have built-in external “helper” programs, one of which is msnt_auth which is far easier to get to work against an active directory domain than ntlm_auth. CAVEAT, this does not work with transparent proxying, however, this works very well if you autoconfig browsers or use group policy to point the machines on your network to the squid box. The following steps are what I did to get it to work. More »