AS3257 213.228.216.0/21 CIDR and IP Range Summary.ASN: 3257 - GTT Communications Inc.Host Count: 2046Addressable IPs: 2048213.228.216.0/24213.228.217.0/24213.228.218.0/24213.228.219.0/24213.228.220.0/24213.228.221.0/24213.228.222.0/24213.228.223.0/24