2001:ec0:4000::/40 - TOT6NET-AP-20040415
inet6num: 2001:ec0::/32 netname: TOT6NET-AP-20040415 descr: TOT public company limited descr: Telecommunication Provider, Network Service Provider (NSP) descr: Internet Service Provider (ISP) in Thailand country: TH org: ORG-TPCL1-AP tech-c: tk56-ap admin-c: pa82-ap tech-c: ss110-ap remarks: new ipv6 core network for the next generation and core ipv6 in remarks: thailand. mnt-by: APNIC-HM mnt-lower: maint-th-tot mnt-irt: IRT-TOT-TH status: ALLOCATED PORTABLE last-modified: 2017-08-29T23:00:08Z source: APNIC
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.