Port Channels and Channel groups

[glinskim]

Trying to understand port channel and Channel Groups.  Does it matter that the Port Channel and Channel Group on the main switch is one number ie. 208 and the Port Channel and Channel Group on the uplinked switch are different ie. 8.  I thought that as long as the Switchport Trunk VLan and the Switchport mode is Trunk on both there will not be a VLan mismatch.
Thanks as always for feedback

[Reza Sharifi · Accepted solution]

Portchannel or channel group numbers (same thing) are locally significant. So, you can use 2 on one side and 20 on the other side. Usually, for consistency and ease of management, it is better to use the same number on both sides of the connection.

HTH

[glinskim]

Thanks, as I mentioned thought that was the case but wanted to confirm.  Don't need a Vlan mismatch causing any problems

[MHM Cisco World]

One by one 

Port channel or channel group is local to SW' but engineer always use same number in both neighbor for easy admin and troubleshooting.

Vlan mismatch in one SW between port member and port channel will make PO not work or PO not add port member with mismatch vlan

Mismatch vlan between two neighbor SW connect via PO will make STP blk the all PO or blk missing vlan depend on which STP ypu use.

MHM

[Joseph W. Doherty]

A side note about Etherchannels.

Cisco switches usually offer multiple load balancing choices; insure you pick one that's best for your traffic especially as some switches default (can vary between switch series) choice might be a bad choice for your traffic.

Also, the LB only applies to egress traffic and the other side switch can use a different LB choice.

[Joseph W. Doherty]

Oh, and another side note about Etherchannels.

A single flow will only use one link.  Multiple flows (ideally) use multiple links, but Etherchannel doesn't do any actual load balancing based on link loadings.  So, for example, a dual Etherchannel, usually won't double your effective bandwidth, but you may see about a 50% effective bandwidth improvement.