AS17225 AT&T Enhanced Network Services
184.108.40.206/20 - ATTWH-206-17-97-0-24-0902035645
NetHandle: NET-206-17-97-0-1 OrgID: C02148136 Parent: NET-206-16-0-0-1 NetName: ATTWH-206-17-97-0-24-0902035645 NetRange: 220.127.116.11 - 18.104.22.168 NetType: reassignment RegDate: 2009-02-03 Updated: 2009-02-03 Source: ARIN OrgID: C02148136 OrgName: CI - AT&T Connect SID-16898 CanAllocate: Street: 25 First Street City: Cambridge State/Prov: MA Country: US PostalCode: 02141 RegDate: 2009-02-03 Updated: 2011-03-19 Source: ARIN
IP address subranges within this IP range
IP address ranges, or netblocks, are groups of related IP addresses. They are usually represented as a base IP address, followed by a slash, and then a netmask which represents how many IP addresses are contained within the netblock. This format is known as CIDR. You'll also sometimes see netblocks given as a start ip address, and an end ip address, or an ip address range.
Traffic works its way around the internet based on the routing table, which contains a list of networks and their associated netblocks.