2001:67c:2564::/48 - UTNET-IPv6
inet6num: 2001,67c,2564,,/48 netname: UTNET-IPv6 country: NL org: ORG-UT18-RIPE sponsoring-org: ORG-Sb3-RIPE admin-c: GM3191-RIPE tech-c: GM3191-RIPE status: ASSIGNED PI mnt-by: RIPE-NCC-END-MNT mnt-by: SN-LIR-MNT mnt-routes: AS1103-MNT mnt-domains: SN-LIR-MNT created: 2011-11-04T16,07,03Z last-modified: 2016-04-14T08,42,34Z source: RIPE organisation: ORG-UT18-RIPE org-name: Universiteit Twente org-type: OTHER descr: Drienerlolaan 5 descr: P.O. Box 217 descr: NL - 7500 AE Enschede address: The Netherlands phone: +31 53 489 2311 e-mail: firstname.lastname@example.org admin-c: Ins20-RIPE tech-c: Ins20-RIPE mnt-by: SN-LIR-MNT mnt-ref: SN-LIR-MNT abuse-c: SNS1-RIPE created: 2015-05-27T07,46,16Z last-modified: 2015-05-27T07,46,16Z source: RIPE person: Gert Meijerink address: Universiteit Twente address: P.O. Box 217 address: NL-7500 AE Enschede address: The Netherlands phone: +31 53 892326 e-mail: email@example.com nic-hdl: GM3191-RIPE remarks: This object is no longer maintained by firstname.lastname@example.org remarks: and is or may soon become obsolete. notify: info@SURFnet.nl mnt-by: SN-LIR-MNT mnt-by: SN-LIR-MNT created: 1970-01-01T00,00,00Z last-modified: 2001-09-22T07,19,05Z source: RIPE route6: 2001,67c,2564,,/48 descr: University Twente IPv6 origin: AS1133 mnt-by: AS1103-MNT mnt-routes: AS1103-MNT created: 2011-11-11T11,26,32Z last-modified: 2011-11-11T11,26,32Z source: RIPE
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.