Hi all.. this one seems to have stumped even the community forums on CCO ;) Anyone else seen this behaviour? (It's not actually a problem as such since the MEC port-channels are actually working fine, just unexpected the way that it has done it...) We have a few paris of VSS running, and having brought the down-stream access-switches online using MEC we note that the active port-channel that they bind under isn't actually the one configured, but rather a CLONE of the configured one which appears to be dynamically generated. In our case, all ports and port-channel configurations are set to dot1q encapsulation and trunk mode active. For example, we have about 20 3560s MEC'd to the VSS: the MEC comes up, but under a slightly different port-channel identifier: Here's the 3560 side: interface status: Gi0/49 connected trunk a-full a-1000 1000BaseSX SFP Gi0/50 connected trunk a-full a-1000 1000BaseSX SFP Gi0/51 connected trunk a-full a-1000 1000BaseSX SFP Gi0/52 connected trunk a-full a-1000 1000BaseSX SFP #sh int po1 | i Member Members in this channel: Gi0/49 Gi0/50 Gi0/51 Gi0/52 Here's the VSS side: Interface status: Po11 CISCO C3560 A01 notconnect 1 auto auto Po11A connected trunk a-full a-1000 ^^^^ Po11A is not actually configured, but appears to be cloned from Po11 #sh int po11A | i Member Members in this channel: Gi1/1/33 Gi1/1/34 Gi2/1/41 Gi2/1/42 #sh cdp nei | i hacc01-d hacc01-d Gig 2/1/42 140 S I WS-C3560G Gig 0/50 hacc01-d Gig 2/1/41 140 S I WS-C3560G Gig 0/49 hacc01-d Gig 1/1/34 161 S I WS-C3560G Gig 0/52 hacc01-d Gig 1/1/33 161 S | WS-C3560G Gig 0/51 Essentially, for all of the MEC connections, the VSS has created a clone of the configured port-channel to bind the actual physical connections, rather than binding them under the configured port-channel (and suffixed the port-channel number with A or B depending on which chassis was first to bind). Config for port-channel and interfaces all match: VSS SIDE: interface Port-channel11 description CISCO C3560 A01 switchport switchport trunk encapsulation dot1q switchport trunk allowed vlan 40-48,51,400 switchport mode trunk mtu 9216 end Physical ports are the same config, with channel-group 11 mode active (and repeated for 20 different port-channels each with 4 ports) ACCESS Side: interface Port-channel1 description DIST-VSS-EQX1 switchport switchport trunk encapsulation dot1q switchport trunk allowed vlan 40-48,51,400 switchport mode trunk mtu 9216 end Similarly, physical ports are the same with channel-group 1 mode active I'm not overly worried about it since the MEC is working with the dynamically generated port-channel, and traffic is flowing correctly... just curious as to why it uses a clone of the configured port-channel, rather than the actual configured port-channel itself. Just find that a bit strange. Thanks, Leland