Network & Infrastructure / EVPN, VXLAN & Data Center Fabrics
Duplicate tenant IP addresses with different EVPN MAC owners
Two hosts advertise the same tenant IP from different racks, producing intermittent neighbor resolution. MAC reachability can be individually correct while IP ownership is ambiguous.
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 MAC/IP advertisements, host inventory, DHCP records and duplicate-detection events for the same VRF. Establish whether the address is an intentional anycast service before declaring a conflict.
Explain the result
A shared IP is not inherently invalid, but ordinary hosts and intentional anycast services require different designs. Conflicting ownership can make suppression and neighbor caches alternate between endpoints.
Plan the fix
Resolve unintended duplication at the provisioning source and clear stale state only through the supported procedure. Preserve explicitly designed anycast behavior instead of enforcing a blanket one-owner rule.
Check the result and rollback
Verify stable ownership from multiple VTEPs and successful application traffic over cache refresh cycles. Revert if remediation disrupts an intentional service or another duplicate appears from the same template.