In the case of a Catalyst 6000 or 6500 series switch, multilayer switching functions in much the same fashion manner as the example illustrated in the NFFC section just considered. However, there are some differences in terms of the hardware used. In the case of a Catalyst 6000 or 6500, three main hardware components are involved, as outlined below.
Catalyst Supervisor. The Catalyst Supervisor contains the CPU and ASICs used to carry out Layer 2 switching functions.
Policy Feature Card (PFC). Much like an NFFC, a Policy Feature Card provides the “shortcut” caching services that allow routed packets to be written without each packet needing to be passed to the route processor. The PFC is typically provided as a daughtercard on the same board as the MSFC.
Multilayer Switch Feature Card (MSFC). The MSFC effectively provides the high-performance routing functions for a multilayer Catalyst 6000 or 6500. The MSFC route processor is another daughtercard on an MSFC module.