Can I use vPC between core and aggregation layer switches

[deepaksoftware]

Hi,

I have usual three layer architecture network. aggregation is consist of cisco 6509 and core consists of 6506. Now would like to get replace both layer with Nexus 5K and 7K. Its usual L3 between core and aggregation. Just was wondering if vPC ca be utilize between core and agg, via using SVI and addition L3 link for routing between vPC peers. Will this design work or not? I search and few posts claim is possible with few additional command like peer-gateway and layer3 peer-gateway. Please see topology and let me know any info possible. Thanks in advanced.

[cassiolange · Accepted solution]

Hello 

This design will work. In this in this scenario you will need FHRP. Remember HSRP/VRRP on nexus will be active/active from data plane.
Layer-3 peer route will not decrement TTL when packet is routed. Is necessary when you have dynamic routing protocols.

This document can help you. 

https://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf

Good lucks, 

Regards,

[deepaksoftware]

Hi Cassiolange,

Thanks for your help and I appreciated. I think you are right. Only there are some caveat like I'll have to use F series card and all that but it should work. My manager will have meeting with cisco regarding purchase where he'll be validating this design as well. And I'll have to create another VLAN for SVI to route traffic between 5K and 7K by distributing into OSPF, is that right thinking? 

But hey thanks for your help and please let me know if you think of any obstacle could be along the way.

Regards

Deepak