Objectives
The simulator ticks each one as soon as the network meets it.
Find why L1’s VTEP is down, and fix it.
Find why L2 does not carry VLAN 10 over VXLAN, and fix it.
Find why L2 answers no gateway traffic, and fix it.
Ping PC2 (192.168.10.20) from PC1.
Ping PC3 (192.168.20.10) from PC1.
Before you start
Work up the layers: show bgp l2vpn evpn summary, then show vxlan interface (the State line gives the VTEP’s reason), then show vxlan vlanvnimap on both leaves, then show running-configuration for the anycast lines. Compare the two leaves: most faults show up as a difference.
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.
