Which command will allow you to verify that Cisco Express Forwarding is enabled on interface GigabitEthernet 0/0?
- show interface cef GigabitEthernet 0/0
- show ip interface GigabitEthernet 0/0 cef
- show ip interface cef
- show ip interface GigabitEthernet 0/0
Explanation: Cisco Express Forwarding (CEF) is defined in the sources as the fastest switching mechanism and the default mode for Cisco devices. It operates by separating the control plane, which builds the forwarding tables in software, from the data plane, which forwards traffic using hardware. CEF relies on two primary hardware-based tables: the Forwarding Information Base (FIB), which contains destination prefixes, and the adjacency table, which stores Layer 2 next-hop and header rewrite information.
To verify that CEF is enabled and functioning on a specific interface, the command show ip interface [interface-id] is used. This command provides a comprehensive report of the IP configuration and status for the interface, including a specific line indicating whether IP CEF switching is enabled.
Related exam: Modules 1 – 7: Checkpoint Exam: Network Switching Answers (CCNP ENCOR v9)
