I want to use the ntlm helper not basic. When I use the ntlm helper it just keeps asking for the username and password over and over. Using the basic helper works fine. # /usr/bin/ntlm_auth --username=user1 --domain=testdomain --password=userpassword NT_STATUS_OK: Success (0x0) squid.conf # NTLM Authentiation auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp auth_param ntlm children 30 # Basic authentication #auth_param basic program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-basic #auth_param basic children 5 #auth_param basic realm Outlook Web Access #auth_param basic credentialsttl 2 hours acl Allowed proxy_auth REQUIRED http_access allow Allowed http_access deny all