Network & Infrastructure / EVPN, VXLAN & Data Center Fabrics
Distributed anycast gateway consistency across leaves
A tenant works on one rack but fails after moving to another. The distributed gateway IP exists everywhere, yet gateway MAC or subnet configuration differs between leaf switches.
Environment and inputs: BGP EVPN overlays on a routed underlay; supported route types and multihoming behavior depend on the network OS. Diagnostic/design example; not tested on production equipment.
Collect the evidence
Compare gateway IP/MAC, tenant VRF, subnet prefix, local VLAN mapping and advertised host routes on every participating leaf. Include IPv6 router and neighbor behavior when dual stack is enabled.
Explain the result
Anycast gateway designs rely on deliberately consistent gateway identity and correct tenant context. A familiar gateway address alone does not guarantee the host reaches the same routed service after migration.
Plan the fix
Correct the shared gateway definition through the inventory and template. Treat changes to an established gateway MAC as a migration requiring host-neighbor considerations rather than a harmless cosmetic edit.
Check the result and rollback
Test local and remote subnet traffic before and after migration, checking tenant isolation. Restore the prior definition if hosts retain incompatible neighbor state or traffic enters the wrong VRF.