Cisco CCNA (200-301)Network AccessHard
A network technician is configuring an EtherChannel using LACP between two Cisco Catalyst 2960 switches. The technician has bundled four physical interfaces (Gi0/1 to Gi0/4) into Port-channel1. After configuration, the `show etherchannel summary` command output shows the following for Port-channel1: `Po1(SD)`. What does the 'D' flag indicate in this output?
- AThe Port-channel is in a Down state.
- BThe Port-channel is configured for PAgP.
- CThe Port-channel is configured for Dynamic LACP.
- DThe Port-channel is in a suspended state.
Show answer & explanationAnswer & explanation
Correct answer: D. The Port-channel is in a suspended state.
In the `show etherchannel summary` output, the 'D' flag indicates that the Port-channel is in a 'suspended' state. This often happens due to an EtherChannel guard, a protocol mismatch, or a configuration error preventing the bundle from forming or forwarding traffic.
Why the other options are wrong
- A. The 'D' flag does not mean 'Down' in the general sense; it specifically means 'suspended'.
- B. PAgP would typically show 'P' or 'S' flags for protocol state, not 'D' for suspended.
- C. 'Dynamic' is implied by LACP, but 'D' specifically means suspended.
EtherChannel Summary Flags
Flags in the `show etherchannel summary` command output provide quick status indications for an EtherChannel bundle on Cisco switches.
- S: Layer 2 EtherChannel.
- U: In use (forwarding).
- D: Individual port state is down or suspended.
- P: Port-channel in PAgP mode.
- L: Port-channel in LACP mode.
Memory trick: SUM: S-L2, U-Up, D-Down, L-LACP, P-PAgP.