Objectives
The simulator ticks each one as soon as the network meets it.
On both leaves: ip virtual-router mac-address 00:00:5e:00:01:01, and ip vrf Vrf-T1.
Under evpn: router-mac, then vrf Vrf-T1 with vni 50001 and route-target auto.
Put the VLAN interfaces in the VRF. Give each its own address (192.168..201 on L1, .202 on L2) and ip virtual-router address 192.168..254.
show evpn vrf on L1: Vrf-T1 is up.
Ping PC3 (192.168.20.10) from PC1.
Before you start
The gateway is the same on every leaf, so a host moves without changing it. The VRF’s L3 VNI carries routed traffic between leaves: L1 has a /32 route to PC3 via L2’s VTEP. See it with show ip route vrf Vrf-T1.
Concept
BGP EVPN: a control plane for VXLAN
BGP EVPN replaces flood-and-learn with BGP routes in the L2VPN EVPN address family. Each VTEP advertises an inclusive-multicast route (type 3) per VNI, so the others know to replicate to it, and a MAC route (type 2) per local host, so remote MACs are known before any traffic flows. A spine is usually the iBGP route reflector.
Concept
A leaf-spine fabric on Dell switches
Every leaf connects to every spine, and no leaf connects to another leaf, so any two leaves are two hops apart over several equal paths. eBGP routes between loopbacks form the underlay, usually with one ASN per leaf pair. EVPN then runs on the same BGP sessions: VTEPs announce their VNIs and hosts, and tunnels form from those routes. SONiC can peer without link addresses: ipv6 enable and neighbor interface are enough.
