Add a non-vPC vlan to a vPC member portchannel

[Liyanage]

Could you add a non-vPC vlan (a vlan that is not on the vPC Peer Link) successfully to a vPC member port (a vPC portchannel) without the added vlan getting suspended. Please see attached topology diagram. Your advice is much appreciated. 

[Reza Sharifi]

No, In a VPC environment, all VLANs need to be added to the VPC peer-link if not. you will have layer-2 VPC inconsistency.

HTH

[Liyanage]

Hi Reza,

Thank you for getting back on this. It is much appreciated. Could you kindly point me to any Cisco/alternative documentation on this ?

[balaji.bandi]

no that is not valid, what is the use case here, i do not see any advantage orphan ports with VLAN 6 ?

can you explain the reason why you thinking to do it that way?

[Liyanage]

Hi Balaji,

Thank you for the response. It is much appreciated. 

We intend to create a genuine Autonomous System (AS) for the vlans 2,3,4 & 5 and the access switch will act as a router providing the BGP adjacency (neighbor relationships) to the N7K1 & N7K2 using vlan 6 with a /29 subnet. The reason for having the vlan 6 as a non-vPC is to provide resiliency at layer3 rather than in layer2 and avoid any implication from vPC peer-link failures. Please note that vlans 2,3,4 & 5 are some legacy vlans that are also located in other access switches connected via L2 to N7K1 & N7K2 but currently routed via the access switch in the figure using OSPF and redistributed to the main BGP. We intend to get rid of the OSPF for redistribution and have a BGP peering instead as the above networks to be operated as a separate entity. 

[balaji.bandi]

if you looking the requirement as per descfription, suggest to use Point to Point link rather vPC or port-channel,

each device connet to only parent device and configured p2p link -   any way BGP will fail over when other peer not available.

[Liyanage]

Hi Balaji,

Thank you for the clarification. It is much appreciated.

However, the decision not to p2p links was due to a particular behavior (state tracking table) in the non-Cisco router (in place of the access switch shown in the diagram).

Could you please point me to any documentation Cisco/non-cisco for further information on the vPC behavior in this situation?

Thank you.