Let's suppose that we have a common Clos EVPN/VXLAN-based DC fabric with IP gateways on leaves (anycast gateways). Also there is a lot of different IP VRFs inside a fabric where end hosts reside. What is an optimal way to connect all those VRFs to the MPLS-based backbone network (there is no EVPN at the backbone level, only IP VPNs).
I can imagine the following options:
Option-A style. For each VRF create BGPv4 session between Border Leaf and DC Edge router. A lot of config overhead, poor scaling.
Introduce DC Edge router into EVPN fabric, exchange EVPN routes with the fabric via BGP EVPN, create all necessary fabric VRFs at DC Edge router. In this option DC Edge router must perform MPLS-to-VXLAN transition and vice-versa. I'm not sure this is possible at the hardware level (DC Edge router is Juniper MX) and I cannot find any guides discovering this topic.
I've added the scheme to illustrate my goal.
I just want to connect VRFs A and B from the left to the same VRFs on the right with the following constraints:
- No need for stretching EVPN routes inside all Backbone network.
- No need for stretching IP VPN (MPLS) routes inside DC network.