NX OS - NDFC - 2 SITES COLLAPSED BGW/SPINE TOPOLOGY MP BGP EVPN VXLAN

[dugolotti]

Hello all, we have a 2 sites DC, and the DCI between them, consists of 2 DWDM 10Gbps links. In each site we have a Fabric  composed by 2 Spine and several Leaf. We have a cluster of NDFC in one site and a UCS for NDI. My question is the following, it is possible to have collapsed the role of Border Gateway and Spine, where the 2 links DWDM (DCI) will be connected over the Spine? The local Spine/BGW will have a L3 link between them in order to forma a "square".  I haven't found any design guide that validates this topology but this should be work. Do anyone has dome document or have tried this topology with success?

Thank you

[Helena Cornic]

Hello,

You can find a reference in the VXLAN EVPN Multi-Site Design and Deployment White Paper ( https://www.cisco.com/c/en/us/products/collateral/switches/nexus-9000-series-switches/white-paper-c11-739942.html#Designconsiderations) :

"BGW-on-spine model

The previous topologies used dedicated BGW nodes. In the BGW-on-spine model (Figure 15), the BGW is co-located with the spine of the site-internal network (fabric)"

[dugolotti]

Hello Helena, thanks for sharing the link. I've seen that guide but if I understand well, it describes a topology with Spine and Superspine. We have Leaf and Spine only with DCI Links (2x10Gbps) connected directly to Spines. Every couple of Spines have a L3 link in order to have a square.

Thank you  

[Helena Cornic · Accepted solution]

Hello,

It was to clarify that the BGW role can be placed on the Spine, independently of the DCI option. In your case, it is the BGW back to back option with a L3 link as recommended.

It is true that the document doesn't describe the two design choices together but it works.