I have a 2 switch stack and both have a fiber trunk link back to there own 6500 running in vss. I currently have them configured with "channel-group 15 mode on" which appear to be working fine. My question is when I run the command for port-channnel info. I get unknown protocol. Am I missing something? Should I be running it in pagp? If so how? Or should I run it as lacp? If so how? Benefits? Disadvanages?