AS7018 12.21.240.0/20 CIDR and IP Range Summary.ASN: 7018 - AT&T Services Inc.Host Count: 4094Addressable IPs: 409612.21.240.0/2412.21.241.0/2412.21.242.0/2412.21.243.0/2412.21.244.0/2412.21.245.0/2412.21.246.0/2412.21.247.0/2412.21.248.0/2412.21.249.0/2412.21.250.0/2412.21.251.0/2412.21.252.0/2412.21.253.0/2412.21.254.0/2412.21.255.0/24