AS4643 203.16.88.0/21 CIDR and IP Range Summary.ASN: 4643 - Optus Customer NetworkHost Count: 2046Addressable IPs: 2048203.16.88.0/24203.16.89.0/24203.16.90.0/24203.16.91.0/24203.16.92.0/24203.16.93.0/24203.16.94.0/24203.16.95.0/24