Symptom

Port-channel interface does not seem to set the MTU correctly even though 'show run interface' shows the mtu configured under the port-channel interface. e.g.: jumbo frames may be hardware rate limited even though MTU is configured to allow jumbo frames.

Conditions

1) If the MTU is configured on the port-channel member interface before creating the port-channel interface, the MTU may not be set correctly on the port-channel interface itself. 2) If the MTU was never configured on the member port, but was configured on the port-channel then the member port MTU does not reflect the port-channel MTU once it is removed from the port-channel.

Workaround

For 1) configure the MTU on the port-channel interface itself, instead of the member interfaces. Alternatively, shut/no shut on the port-channel will also apply the MTU correctly. For 2) configure the MTU on the member port after it is removed from the port-channel.

Further Problem Description