AS7018 12.51.136.0/21 CIDR and IP Range Summary.ASN: 7018 - AT&T Services Inc.Host Count: 2046Addressable IPs: 204812.51.136.0/2412.51.137.0/2412.51.138.0/2412.51.139.0/2412.51.140.0/2412.51.141.0/2412.51.142.0/2412.51.143.0/24