|  | 2.2 | WANs and Router
| 2.2.3 | Semester 2 lab topology
The Semester 2 lab topology should be thought of as an enterprise WAN for a medium-sized company with offices around the world. It is not connected to the Internet; it is the company's private network. Also, the topology, as shown, is not redundant -- a failure of any router along the chain will break the network. This network of networks, under a common administration (the company) is called an autonomous system. - The Internet is a network of autonomous systems, each of which has routers that typically play one of four roles. internal routers -- internal to one area area border routers -- connect two or more areas backbone routers -- primary paths for traffic that is most often sourced from, and destined for, other networks autonomous system (AS) boundary routers -- communicate with routers in other autonomous systems While no one entity controls them, the typical entities are: corporations (e.g. MCI Worldcom, Sprint, AT&T, Qwest, UUNet, France Telecom) universities (e.g. University of Illinois, Stanford University) research institutes (e.g. CERN in Switzerland) Internet Service Providers (ISPs) Although the Semester 2 topology is not a model of the Internet, it is a model of one topology that might represent an autonomous system. The protocol that is routed almost universally is IP; the routing protocol Border Gateway Protocol (BGP) is widely used among the Internet routers. Router A is in Kuala Lumpur, Router B in San Francisco, Router C in New York City, and Router D and E in Paris. Each of the routers connects to an office or campus LAN. The connections from A-B, B-C, and C-D are leased T1 lines that are attached to the routers' serial interfaces. Note that each router has an Ethernet LAN attached to it. Typical devices on Ethernet LANs, hosts are shown along with their console cables to allow configuration and display of the routers' contents. Also note that four of the routers have wide-area serial connections between them.
| Lab Activity
| This lab will help you develop an understanding of how the Cisco lab routers are set up and connected for the Semester 2 topology. You will examine and document the physical connections between these routers and the other lab hardware components such as hubs, switches, and workstations.

| Lab Activity

This lab will help you develop an understanding of how the Cisco lab routers and workstations are configured for the Semester 2 topology. You will use IOS commands to examine and document the IP network configurations of each router.