Why do you need "channel-protocol" command in the interface config mode while configuring etherchannel when you define the protocol to use by defining desirable/auto or active/passive with channel-group n mode command? Appreciate if someone can throw some light on this? Thanks Guys
You can use the channel-protocol command to restrict anyone from selecting a mode that is not applicable to the selected protocol.
for pagp desirable/auto auto/desirable desirable/desirable, but no auto auto
for lacp active/passive passive/active active active, but no passive passive
i prefer simply on... there are many who will give you a great deal of reasons for a negotiation protocol, for whatever that's worth... the only compelling reason for me to use lacp is if i was connecting to a server lacp capable nic...
there are many discussions posted here for or against... the deciding factor is you... my advice, as always is to learn the fine points of all options so that you can truly understand why to discard them...
The thing is that when you have the "channel-protocol <PROTOCOL>" command you are hardcoding that specific protocol under the interface. The PAgP works in two modes; desirable, and auto. If you set the protocol to PAgP you will not be able to configure the "channel-group 1 mode active/passive" command, since these belongs to LACP, and viceversa.