AS23520 72.252.72.0/21 CIDR and IP Range Summary.ASN: 23520 - Columbus Networks USA Inc.Host Count: 2046Addressable IPs: 204872.252.72.0/2472.252.73.0/2472.252.74.0/2472.252.75.0/2472.252.76.0/2472.252.77.0/2472.252.78.0/2472.252.79.0/24