Which Cisco IOS router command would disable Cisco Express Forwarding on a specific interface?
- router(config)# no ip route-cache cef
- router(config-if)# no ip cef
- router(config)# no ip cef
- router(config-if)# no ip route-cache cef
Explanation: Cisco Express Forwarding (CEF) is the default and most efficient switching mechanism used by Cisco routers to forward packets at high speeds using hardware-based tables like the FIB and adjacency tables. While CEF is typically enabled globally on the device, it can be disabled on a specific interface by using the command no ip route-cache cef in interface configuration mode. This action is often taken during troubleshooting to force the router to use process switching for that specific interface, allowing the CPU to examine every packet individually, although this significantly degrades performance. It is important to note that while the provided sources describe the characteristics of CEF, fast switching (route caching), and process switching, the specific command syntax is based on general Cisco IOS knowledge and is not explicitly detailed in the provided excerpts.
Related exam: Modules 1 – 7: Checkpoint Exam: Network Switching Answers (CCNP ENCOR v9)
