Objectives
The simulator ticks each one as soon as the network meets it.
On both leaves: ip anycast-mac-address 00:00:5e:00:01:01, ip anycast-address enable, and ip vrf Vrf-T1.
Put each host VLAN in Vrf-T1 with ip anycast-address 192.168..254/24.
Create VLAN 3001 in Vrf-T1 for the L3 VNI. Under interface vxlan vtep1: map vni 50001 vlan 3001, then map vni 50001 vrf Vrf-T1.
Under router bgp vrf Vrf-T1: redistribute connected, and advertise ipv4 unicast in the l2vpn evpn family. show vxlan vrfvnimap on L1 lists Vrf-T1.
Ping PC3 (192.168.20.10) from PC1.
Before you start
The VLAN for an L3 VNI carries no hosts and needs no address: it only ties the VNI to the VRF. Without ip anycast-address enable, the gateway stays down, which is a common first mistake. show ip route vrf Vrf-T1 shows PC3 as a /32 via L2’s VTEP.
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.
