AS10508 University of Arkansas
2604:fc00::/32 - UARKNET
V6NetHandle: NET6-2604-FC00-1 OrgID: UNIVER-249 Parent: NET6-2600-1 NetName: UARKNET NetRange: 2604:FC00:: - 2604:FC00:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF NetType: allocation OriginAS: 10508 RegDate: 2010-07-19 Updated: 2012-03-02 Source: ARIN OrgID: UNIVER-249 OrgName: University of Arkansas CanAllocate: Street: 155 Razorback Road, ADSB 220 City: Fayetteville State/Prov: AR Country: US PostalCode: 72701 RegDate: 1970-01-01 Updated: 2017-08-18 OrgAdminHandle: UA2-ORG-ARIN OrgAbuseHandle: UA2-ORG-ARIN OrgTechHandle: UA2-ORG-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.