Understanding the Network: A Practical Guide to Internetworking

Layer 2 LAN Switching Fundamentals

Layer 2 switches come in two basic formats: workgroup and enterprise. Workgroup switches have a fixed port count, usually between 12 to 24 ports, and one or two port expansion modules which are provided either for adding some of the same media or for high-speed uplink ports. Enterprise switches are essentially multislot chassis with power supplies. The chassis provides one or more interconnect buses that connect the switch modules. Some enterprise chassis vendors require a chassis control module, which controls the switch module's access to the chassis backplane. This, of course, creates a central point of failure and typically uses up one of the chassis slots. Other vendors build backplane management into the ...