Cisco CCNA (200-301)Network AccessMedium
An engineer has configured an EtherChannel using LACP between two Cisco Catalyst switches, SW1 and SW2. The configuration on SW1 for physical interfaces Gi0/1 and Gi0/2 includes 'channel-group 1 mode active'. The configuration on SW2 for physical interfaces Gi0/1 and Gi0/2 includes 'channel-group 1 mode passive'. However, the EtherChannel is not operational. Which of the following commands on SW1 would provide the most relevant information to troubleshoot the LACP status?
- Ashow cdp neighbors
- Bshow ip interface brief
- Cshow interfaces status
- Dshow etherchannel summary
Show answer & explanationAnswer & explanation
Correct answer: D. show etherchannel summary
The 'show etherchannel summary' command provides a concise overview of all EtherChannels, including their operational status (e.g., 'U' for in use, 'D' for down), the LACP protocol being used, and the member ports with their individual status flags. This is the most direct command to check EtherChannel and LACP operational status.
Why the other options are wrong
- A. Shows information about directly connected Cisco devices via CDP, not EtherChannel status.
- B. Shows IP address and interface status, but not EtherChannel or LACP specific information.
- C. Shows interface line protocol and administrative status, but not specific EtherChannel or LACP details.
EtherChannel Summary Command
The 'show etherchannel summary' command is used to quickly verify the operational status, protocol, and member interfaces of all configured EtherChannels on a Cisco switch.
- Displays group number, protocol (LACP, PAgP, or On), and port-channel interface.
- Shows individual member ports and their flags (P for bundled, S for suspended, I for standalone).
- Indicates the overall status of the Port-Channel interface (e.g., U for up, D for down).
Memory trick: EtherChannel Summary: See the whole story, quickly.