Cisco Express Forwarding (CEF) is a Layer 3 switching technology designed for routers. It uses a method that optimizes route lookups to achieve very fast forwarding. CEF uses two tables to store the information needed for routing: the Forwarding Information Database (FIB) and the adjacency table.
CEF is supported on routers 1700, 2600, 3600, 3700, 7100, 7200, 7400, 7500, 7600, and the Catalyst 6500 and 12000 series.
There are two CEF modes:
Central CEF— The route processor handles CEF and adjacency tables. This mode is supported on router series 1700 to 7500.
Distributed CEF (dCEF)— This mode is used on distributed hardware architectures such as the Cisco 7500 VIP and Cisco 12000 line cards. dCEF performs ...