Chapter 2. LAN Protocols: Configuring Catalyst Ethernet and Token Ring Switches

In the realm of networking, no technology is outpacing that of local-area networks (LANs). In less than a decade , LANs have become common in many homes and are a "must" for any small business. Many, if not all, new commercial buildings are wired with some type of copper or fiber cable plant for local-area networking. Even when you travel, many hotels offer the use of a LAN to access the Internet. Many new residential communities are incorporating what you might call c ommunity-area networks, or CANs, in which homes will be connected through LANs to provide Internet service or another related service.

Not only is the number of LANs multiplying, but bandwidth also is multiplying exponentially. The standards that have been written and adopted for LAN protocols in the last 10 years have been tremendous. For example, in March 2002, 10-Gb Ethernet, 802.3ae, is scheduled for formal ratification, and 100-Gb Ethernet seems inevitable. To put leaps in technology like this in perspective, we use the less than scientific "Twinkie Theory." If a Twinkie represents the bandwidth available on a 10-Mb Ethernet network, a 10-Gb Ethernet network would be a Twinkie roughly 333 feet long and 100 feet tall ”now that's a big Twinkie!

NOTE

A community-area network (CAN) can be defined as one or more personal homes sharing a common networking architecture.

LAN protocols have changed rapidly , and there have been many winners and losers in the battle for the LAN. Standards such as 100VG AnyLAN never were fully adapted , whereas other LAN protocols, such as FDDI II, have had all development halted. Ethernet currently dominates the vast majority of the market share, with some estimates putting it at more than 90 percent. Although Token Ring networks are not nearly as plentiful as Ethernet Networks, they still are found at most major data centers running IBM mainframes. For these reasons, this text focuses primarily on Ethernet and Token Ring LANs and switching. Specifically, we will discuss Ethernet and Token Ring LANs, and the configuration of Catalyst 4000/5500/6500, Catalyst 2900XL/3500, and Catalyst 2900 families of switches.