Hello, Me again. I greatly appreciate the help. I'm sorry for my English, I'm trying to improve it. I am trying to connect Squid (Pfsense) to the Samba4 LDAP. I suspect that the error is in the filters, I do not completely understand where I should trace the error. [2017/01/24 20:17:27.603195, 3] ../lib/ldb-samba/ldb_wrap.c:321(ldb_wrap_connect) ldb_wrap open of secrets.ldb [2017/01/24 20:17:27.607318, 3] ../source4/auth/ntlm/auth.c:270(auth_check_password_send) auth_check_password_send: Checking password for unmapped user [CLINICAGUEMES]\[pfsense]@[(null)] auth_check_password_send: mapped user is: [CLINICAGUEMES]\[pfsense]@[(null)] [2017/01/24 20:17:27.615634, 3] ../source4/smbd/process_single.c:114(single_terminate) single_terminate: reason[ldapsrv_call_loop: tstream_read_pdu_blob_recv() - NT_STATUS_CONNECTION_DISCONNECTED] [2017/01/24 20:17:37.838123, 3] ../lib/ldb-samba/ldb_wrap.c:321(ldb_wrap_connect) ldb_wrap open of secrets.ldb [2017/01/24 20:17:37.842162, 3] ../source4/auth/ntlm/auth.c:270(auth_check_password_send) auth_check_password_send: Checking password for unmapped user [CLINICAGUEMES]\[pfsense]@[(null)] auth_check_password_send: mapped user is: [CLINICAGUEMES]\[pfsense]@[(null)] [2017/01/24 20:17:37.850422, 3] ../source4/smbd/process_single.c:114(single_terminate) single_terminate: reason[ldapsrv_call_loop: tstream_read_pdu_blob_recv() - NT_STATUS_CONNECTION_DISCONNECTED] My Conf in Squid auth: LDAP Server User DN: CN=pfsense,OU=PFSENSE,OU=clinicaguemes,DC=clinicaguemes,DC=com,DC=ar LDAP PASS: MyPass of pfsense LDAP Base Domain: OU=Clinicaguemes,DC=clinicaguemes,DC=com,DC=ar LDAP Username DN Attribute: sAMAccountName LDAP Search Filter: (&(objectClass=person)(sAMAccountName=%s)) All users are on: DN: OU=usuarios,OU=clinicaguemes,DC=clinicaguemes,DC=com,DC=ar If they help me what steps to follow to track down the problem I would greatly appreciate them.