EVPN-VXLAN to EVPN VXLAN Tunnel Stitching for DCI

EVPN-VXLAN Tunnel Stitching is an effective technique for interconnecting data centers and extending Layer 2 Ethernet services across geographically distributed locations. This method combines the encapsulation capabilities of VXLAN with the control plane features of EVPN, allowing for the stitching of VXLAN tunnels across different transport networks (e.g., MPLS, IP) at the data center gateway. Tunnels are terminated locally at the gateway, which manages the numerous tunnel operations, thereby alleviating the pressure on the VTEP (VXLAN Tunnel Endpoint) in large data centers that have a vast number of interconnected VTEPs.
This year, we achieved mixed vendor multihoming for the first time, as illustrated in the topology. Nokia and Juniper were multihomed at one site, while Arista and Juniper were multihomed at another site. Both locations had I-ESI and D-path enabled. We then conducted full mesh unicast traffic for testing, which included local routing (using RT-2) as well as cross-domain routing and bridging traffic through the stitching tunnel. Throughout the tests, we observed no duplicate packets or packet loss. In the end, we tested the redundancy function by shutting down and undo shut down for the BGP session on DCI gateway. We observed packet loss but recovered within 3 seconds.
Spirent TestCenter was used as the traffic generator for this test.