AS11957 199.91.136.0/21 CIDR and IP Range Summary.ASN: 11957 - NortonLifeLock Inc.Host Count: 2046Addressable IPs: 2048199.91.136.0/24199.91.137.0/24199.91.138.0/24199.91.139.0/24199.91.140.0/24199.91.141.0/24199.91.142.0/24199.91.143.0/24