>As I >said: with AD 2003 was working well, now with AD2008 is not working.... That doesnât help us, so you upgraded the domain? Regardless, you're not auth'ing to the "same" server so something changed. >auth_param basic >program usr/sbin/squid_ldap_auth -d -v "3" -s "sub" -b "dc=example, dc=org" -D >"cn=example-Auth-User,ou=konten,ou=User city,dc=city,dc=example,dc=org" -w >"fffff" -f "sAMAccountName=%s" -h "ldapserver.ab.example.org" -p "3268" Check the firewall on the 2008 server, it may not be allowing connections to that port for example. More specifically, are you intentionally querying the GC port versus the LDAP port? As I donât know your topology, that may not have a view of what you are looking for...