Objectives
The simulator ticks each one as soon as the network meets it.
On L1 and L2, under router bgp → address-family l2vpn evpn, turn on advertise-all-vni.
Build interface vxlan vtep1: source-ip on Loopback 1 (10.10.10.1, 10.10.10.2).
Map VNI 10010 to VLAN 10.
show bgp l2vpn evpn route on L1: the type-3 route of 10.10.10.2 is there.
Ping PC2 (192.168.10.20) from PC1.
Before you start
source-ip must be an address on a loopback, or the VTEP stays down: show vxlan interface gives the reason. A leaf has one interface vxlan. show vxlan remotevtep lists the tunnels EVPN has built.
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.
