BGP distributes Ethernet reachability
EVPN uses the MP-BGP L2VPN EVPN family, AFI 25 and SAFI 70. A Type 2 MAC/IP Advertisement route carries a MAC address and can include an associated IP address. A receiving PE or overlay endpoint uses the advertisement and service policy to install remote reachability.
A Type 3 Inclusive Multicast Ethernet Tag route can advertise participation used to deliver flooded traffic. Ethernet Auto-Discovery and Ethernet Segment routes help coordinate multihoming. A designated forwarder helps prevent duplicate flooded delivery toward a multihomed segment.
The same control plane can signal different services
EVPN can use MPLS labels or a tunnel encapsulation such as VXLAN to carry traffic. EVPN distributes reachability and service information, while the selected data plane carries the frames.
Multipoint EVPN can connect a shared bridge domain, a service also offered by VPLS. EVPN-VPWS instead signals point-to-point service endpoints. The route types and expected forwarding state depend on the service being deployed.
Try it in a lab
- In a multipoint EVPN lab, place two customer hosts in one service on different PEs. Generate traffic so the local PE learns the first host’s MAC.
- On the remote PE, find the Type 2 route for that MAC, check that its route target matches the service import policy, and confirm that traffic is forwarded to the advertised remote endpoint.
- Withdraw the originating attachment and observe the remote route being withdrawn. Confirm that the stale remote MAC is removed from forwarding state.