auth_param ntlm program /usr/bin/ntlm_auth -helper-protocol=squid-2.5-ntlmssp 
auth_param ntlm children 5
auth_param basic program /usr/bin/ntlm_auth -helper-protocol=squid-2.5-basic 
auth_param basic children 5
auth_param ntlm max_challenge_reuses 0             # Ab Squid 2.6
auth_param ntlm max_challenge_lifetime 60 minutes  # sind diese Zeilen
auth_param ntlm use_ntlm_autonegotiate on          # unnötig!