Hi, currently I've setup Samba 4 (sernet 4.1.8 on debian jessie) successfully as an AD-Server ... domain logins from WIN-Clients etc. are working quite fine. No I'm testing ntlm_auth on cli for further SQUID integration ... *wbinfo output:* wbinfo -a PRAXISAD\\Administrator%xxxxxx plaintext password authentication succeeded challenge/response password authentication succeeded *ntlm_auth with basic helper output:* root at praxis-server:/etc/squid3# ntlm_auth --helper-protocol=squid-2.5-basic --domain=PRAXISAD PRAXISAD\Administrator xxxxxx *OK* *ntlm_auth with ntlmssp helper output:* root at praxis-server:/etc/squid3# ntlm_auth --helper-protocol=squid-2.5-ntlmssp --domain=PRAXISAD PRAXISAD\Administrator xxxxxx *BH SPNEGO request invalid prefix* *ntlm_auth with gss-spnego helper output:** *root at praxis-server:/etc/squid3# ntlm_auth --helper-protocol=gss-spnego --domain=PRAXISAD PRAXISAD\Administrator xxxxxx *BH SPNEGO request invalid prefix* Any ideas what's going wrong here? Thanks & best regards Dirk