EVPN provides a unified BGP control plane that supports both intra- and inter-subnet forwarding within tenant networks. When tenant networks extend across different domains—such as EVPN, BGP IPVPN, or IP address families—clear interworking mechanisms are required between these BGP domains to maintain seamless end-to-end connectivity. draft-ietf-bess-evpn-ipvpn-interworking provides all the details for implementing the service.
In this test, we focused on a gateway-only scenario by simulating two SR-MPLS underlay domains, each with a different overlay: one using EVPN and the other using IPVPNv4. DUT devices acted as gateways, following the procedure outlined in section 8, with Domain Path (D-PATH) enabled to prevent loops. EVPN supports RT-2 and 5. When interworking with other BGP address families for inter-subnet forwarding, the IP prefixes conveyed in these EVPN route types are re-originated into corresponding IPVPNv4 address families, and vice versa. After sending full-mesh unicast traffic, we observed no packet loss, confirming robust connectivity across the setup.