Hello Nicolas
Let me chime in on this conversation as well, it sounds very interesting!
Your approach seems to be a good one, considering you don’t have a traditional WAN solution like MPLS. Using DWDM Point-to-Point links for connecting different DC borders is a great way to ensure high-speed, low-latency connections. Since DWDM operates at the physical layer, it provides a transparent, “protocol-agnostic” and low-latency transport, which is ideal for data center interconnectivity.
Layer 2 VNI over static ingress replication may not be the best choice for multicast traffic because it sends a copy of the traffic to each VTEP that is configured with that VNI. If your network is small, it is probably best for simplicity, but as you get bigger, scalability will be an issue.
Establishing BGP on top of that for control-plane traffic is also a good decision. BGP is a robust, scalable protocol that can handle a large number of routes and is capable of policy-based routing, making it ideal for control-plane traffic management.
Forming VTEP peering on top of that for data plane traffic using L2VPN can also work well. This setup allows for the decoupling of the physical network (underlay) from the virtual network (overlay), providing flexibility and simplifying the network architecture.
Overall, this setup should be able to provide a robust, scalable, and flexible inter-DC solution. However keep in mind that our discussion is a very high-level and hypothetical one. It’s important to remember that every network is unique and the requirements of each will vary, so it’s always a good idea to thoroughly test any suggested setup in a lab environment before deploying it in a production environment.
I hope this has been helpful!
Laz