I have a working NTLM implementation in place and it works great from yum and wget for example. However, when I try to use squid from IE8, it prompts for password and I never see the credentials hit squid, just this for example: 1284395121.846 0 10.8.1.100 TCP_DENIED/407 1798 GET http://google.com/ - NONE/- text/html I have added google.com to IE's local intranet zone and gave that zone low priority so I am not sure where the problem lies. Here's my configuration: auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp --require-membership-of="DOM\\proxyusers" auth_param ntlm children 5 auth_param basic program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-basic --require-membership-of="DOM\\proxyusers" auth_param basic children 5 auth_param basic realm Squid proxy-caching web server auth_param basic credentialsttl 5 hours acl NTLMUsers proxy_auth REQUIRED http_access allow all NTLMUsers I can test fine from the squid server: [root@proxy01a squid]# ntlm_auth --helper-protocol=squid-2.5-basic DOM\jmama password OK What am I missing? Thanks!