Network Warrior, 2nd Edition

Multilayer Switch Models

Cisco offers a variety of multilayer switch models. The line between them has become fuzzy, though, because routers like the 7600 series can take some of the 6500-series switching modules. The 3800 and 2800 series of routers also support a small switching module capable of supporting multiple Ethernet interfaces. These modules actually behave as if they were a separate 3750 switch.

Still, there is no magic all-in-one device. You must choose either a switch with limited routing capabilities or a router with limited switching capabilities. The difference is primarily in how the system internals are designed and which modules are supported. A router is designed differently from a switch, though this is also becoming less true if you consider devices like the CSR-1 (fortunately, the average networking engineer will likely never encounter these behemoths). A router is generally more WAN-centric, whereas a switch is usually more LAN-centric. There are no modules that allow T1 WAN connectivity for the 6500 switches. While you can put 6500-series Ethernet modules in a 7600 router, the backplane capacity is not as high in the router as it is in the switch.

Multilayer switches are divided by chassis type. On the lower end are the single rack unit (1 RU) models that are designed for wiring closets and small installations. Some of these switches can be stacked in a number of ways depending on the model. Some 1 RU models have increased backplane speeds and even support ...