V6NetHandle: NET6-2001-428-2500-24-1 OrgID: SONM Parent: NET6-2001-428-1 NetName: Q1208-2001-0428-2500-0024-0000-0000-0000-0000 NetRange: 2001:428:2500:24:: - 2001:428:2500:24:FFFF:FFFF:FFFF:FFFF NetType: reassignment OriginAS: 209 RegDate: 2017-12-08 Updated: 2017-12-08 Source: ARIN OrgID: SONM OrgName: SECRETARY OFFC NET MTIPS CanAllocate: Street: 1401 CONSTITUTION AVE NW City: WASHINGTON State/Prov: DC Country: US PostalCode: 20230 RegDate: 2013-08-12 Updated: 2013-08-12 OrgTechHandle: BLYTH4-ARIN OrgAdminHandle: BLYTH4-ARIN OrgAbuseHandle: BLYTH4-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.