AS20057 166.186.56.0/21 CIDR and IP Range Summary.ASN: 20057 - AT&T Mobility LLCHost Count: 2046Addressable IPs: 2048166.186.56.0/24166.186.57.0/24166.186.58.0/24166.186.59.0/24166.186.60.0/24166.186.61.0/24166.186.62.0/24166.186.63.0/24