AS12008 NeuStar, Inc.
2001:502:d399::/48 - ULTRADNS-G-V61
V6NetHandle: NET6-2001-502-D399-1 OrgID: ULTRA-13 Parent: NET6-2001-400-0 NetName: ULTRADNS-G-V61 NetRange: 2001:502:D399:: - 2001:502:D399:FFFF:FFFF:FFFF:FFFF:FFFF NetType: allocation RegDate: 2004-11-30 Updated: 2012-03-02 TechHandle: RJ48-ARIN Source: ARIN OrgID: ULTRA-13 OrgName: UltraDNS Corporation CanAllocate: Street: 4600 Center Oak Plaza City: Sterling State/Prov: VA Country: US PostalCode: 20166 Comment: ABUSE NOC 24/7 RegDate: 2004-09-24 Updated: 2017-01-28 OrgAdminHandle: DOMAI79-ARIN OrgTechHandle: RJ48-ARIN OrgAbuseHandle: ABUSE722-ARIN Source: ARIN
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.