AS23520 72.252.16.0/21 CIDR and IP Range Summary.ASN: 23520 - Columbus Networks USA Inc.Host Count: 2046Addressable IPs: 204872.252.16.0/2472.252.17.0/2472.252.18.0/2472.252.19.0/2472.252.20.0/2472.252.21.0/2472.252.22.0/2472.252.23.0/24