AS11172 Alestra, S. de R.L. de C.V.
2001:1248:8018::/48 - INA2
inetnum: 2001:1248::/32 status: allocated owner: Alestra, S. de R.L. de C.V. city: SAN PEDRO GARZA GARCIA country: MX owner-c: INA2 tech-c: INA2 abuse-c: INA2 created: 2008-01-08 changed: 2008-01-08 source: LACNIC nic-hdl: INA2 person: Inet Administrator e-mail: inetadmin@ALESTRA.NET.MX address: Ave. Eugenio Clariond Garza, 175, Cuauhtemoc address: 66450 - San Nicolas de los Garza - NL country: MX phone: +52 81 87486201  created: 20030206 changed: 20110704
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.