EtherChannel configuration errors usually occur because of mismatched parameters on the ports involved. This includes different speeds, different duplexes, and different Spanning Tree Protocol (STP) port values. It is possible that no error message is displayed. This is because mismatched parameters can lead to a loop. To prevent major network issues, spanning tree automatically shuts down the link. Watch for these results when creating the channel to make sure it does what it is intended to do.
To resolve mismatched port channel configurations, perform these steps: