Question

Two switches, SW1 and SW2, are cabled together on ports Gi1/0/1 and Gi1/0/2 to form a Layer 2 EtherChannel. On both switches, the channel-group is configured with 'channel-group 1 mode passive'. After the configuration, the port-channel interface never comes up and 'show etherchannel summary' shows the ports in an independent (I) state. What is the cause and the correct fix?

Accepted Answer

Both sides are using LACP passive mode, so neither initiates negotiation; change at least one side to 'mode active'.

Answer

PAgP and LACP are being mixed; change both sides to 'mode desirable'.

Answer

The ports must be configured as trunks first; add 'switchport mode trunk' to bring the channel up.

Answer

Passive mode requires 'mode on' on the peer; change SW2 to 'mode on' to force the bundle.