AT&T Services, Inc. ATT (NET-12-0-0-0-1) 12.0.0.0 - 12.255.255.255 AT&T Services, Inc. ATTWORLD-MIS-43-128 (NET-12-43-128-0-1) 12.43.128.0 - 12.43.159.255 AT&T Services, Inc. ATTWORLD-MIS-43-128 (NET-12-43-128-0-2) 12.43.128.0 - 12.43.159.255 ENTERPRISE HOLDINGS INC. ENTERPRI823-128 (NET-12-43-128-0-3) 12.43.128.0 - 12.43.143.255