AS17638 123.151.16.0/21 CIDR and IP Range Summary.ASN: 17638 - ASN for TIANJIN Provincial Net of CTHost Count: 2046Addressable IPs: 2048123.151.16.0/24123.151.17.0/24123.151.18.0/24123.151.19.0/24123.151.20.0/24123.151.21.0/24123.151.22.0/24123.151.23.0/24