BGP between two switch VPCs at different DCs

Hey All,

I am trying to share routes over BGP between two DCs.

The connectivity between the DCs is two L2 DCI links configured with point to point networks.

The switches are Nexus 9ks and have a few server networks running HSRP in the VPC.

What I'm trying to achieve in terms of sharing routes between DCs: https://i.imgur.com/13xeB6i.png

Is this the design https://i.imgur.com/R1LZ7hR.png that would be required in terms of individual device peering?

Looking at this document https://www.cisco.com/c/en/us/support/docs/ip/ip-routing/217099-ebgp-peering-over-vpc-on-nexus.html it kinda matches what I'm thinking is required in that second diagram I made.

So on the firewall there would be two separate iBGP peers as you would treat each switch as if they are standalone routers and not in a VPC.

If this was the design that would be required, how would the iBGP peering between the Nexus switches inside the VPC be done?

Would I need a new L3 connection between the Nexus switches? Currently the peer link is a trunked port-channel of two ports. So would I need to create a new transit VLAN on that peer link with SVIs on each switch which I can then use to peer between the two switches?

Would there be any issues in using the same VLAN currently in use between the firewall and the Nexus switches?

I could also technically remove HSRP in this VLAN as well once the BGP routing is implemented.

Are there any other things to consider when setting up this kind of configuration?

There also shouldn't be any reason I couldn't enable ECMP on the Nexus switches either to load-balance between the two DCI links. Right?

We also have VXLAN enabled to extend one of the VLANs between both VPCs, not sure if that would affect anything.

Would be great to hear from anyone who has implemented this type of configuration before and has any advice relating to this scenario or just in general about BGP on VPCs.

Thanks!