2605:8400::/32 - USI-NETBLK-6A
AS10242 US Internet Corp
V6NetHandle: NET6-2605-8400-1 OrgID: USIC Parent: NET6-2600-1 NetName: USI-NETBLK-6A NetRange: 2605:8400:: - 2605:8400:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF NetType: allocation OriginAS: 10242 RegDate: 2010-08-11 Updated: 2012-03-02 TechHandle: KL476-ARIN NOCHandle: KL476-ARIN AbuseHandle: KL476-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.