vPC to service chassis with ACE

[lukaszkhalil]

Hello

Does anybody know if it is possible to connect the 6500 service chassis with ACE in bridge mode by vPC to two aggregation Nexus 7k?

I've tried such configuration and as long as there are two operational links between the 6500 and Nexuses traffic do not pass through the ACE. However if I shut down a link to one of the Nexuses the traffic come back. It does not matter to which, primary or secondary vPC, switch I shut down this link.

Thank you in advance for any helpful information.

Kind regards

[Surya ARBY]

You are probably facing the loop avoidance issue with VPC on nexus 7k. Can you share with us the whole topology ?

[lukaszkhalil]

Hello

I  also thought about it. I attached the lab topology. During the test we check the communication between PC1 and PC2.

[Surya ARBY]

This topology is ok.

You'll have to check the arp cache in agg1 and agg2, and all the macaddress tables in all devices.

Maybe there is an issue with mac-sticky feature ?

[lukaszkhalil]

Hi

I did it, and it seems that the problem is connected with the lack of the L3 interface on the AGG1 switch. Currently it is in the shutdown state.

I made same tests without mac-sticky and the problem is the same.

As long as the traffic can be forwarded to the AGG1 switch then it needs to be forwarded through the peer-link and back via the VPC. As you mentioned before, such communication if forbidden, so the packet must me dropped.

Same situation happens, when we try to send traffic between two vlans connected to the vPC access switch. As long as we have L3 interfaces on both AGG switches everything is fine, but if we shutdown one of them, then all the traffic directed via it will be dropped.

Regards

Lukas

[Surya ARBY]

Yes this is expected. If you shutdown the L3 interface the packet has to transit via the peerlink and cannot leave the system through a VPC as it enters the switch before routing through a VPC.

[lukaszkhalil]

I know, but it is quite dengarous situation in the production. I can imagine that you might need to shutdown one router in the HSRP pair to e.g. change its ip address.

In my opinion this is real big drawback of the VPC.