AS17621 140.206.56.0/21 CIDR and IP Range Summary.ASN: 17621 - China Unicom Shanghai NetworkHost Count: 2046Addressable IPs: 2048140.206.56.0/24140.206.57.0/24140.206.58.0/24140.206.59.0/24140.206.60.0/24140.206.61.0/24140.206.62.0/24140.206.63.0/24