gesh75 BGP EVPN Clos
Do not use for campus L2 or WAN BGP. Not for SD-WAN.
Procedure
- Underlay first: every leaf has eBGP to both spines, IPv4/IPv6 loopbacks advertised, MTU 9216, BFD 300/300.
- Overlay: EVPN AF on the same session or a dedicated one. Route-distinguisher unique per VRF per leaf.
- Confirm IMET + MAC-IP routes. Silent hosts need ARP/ND suppression and anycast GW.
- Multihoming uses ESI, not spanning-tree. LACP on the server, up/up on both leaves.
- Verify:
show bgp evpn route, VXLAN flood-list, and a VM ping across leaves.
protocol bgp {
group SPINE { type external; local-as 65001; neighbor 10.0.0.1 { peer-as 65100; } }
family evpn { signaling; }
}
Anti-patterns
- Never run iBGP with route-reflectors on a two-spine fabric.
- Do not reuse RD/RT across tenants.
Safety
Fabric joins and RT changes go through netops-change-guard with a twin or staging leaf.