Dell SmartFabric OS10 User Guide Release 10.5.3

Overlay remote MAC learn or remove

Remote MACs (MACs of hosts sitting behind remote VTEPs) that are installed by EVPN are not VLT synced to the peer since BGP-EVPN running on each VLT node will install these MACs independently.

Similarly withdrawal of Remote MACs is also not synced to the VLT peer.

MAC clear

The mac clear command issued on one of the VLT nodes is synced to the VLT peer node and all MACs including remote MACs are removed from data-plane - this behavior is the regular VLT behavior.

However, remote MACs installed by EVPN are considered sticky and are re-installed back immediately in the data-plane on both VLT peers.

All EVPN routes advertised by a VLT node corresponding to its local EVIs or MAC addresses are also advertised by the BGP on VLT Peer. These BGP EVPN routes are echo-received back on the peer VLT nodes as remote routes. Since the EVPN routes advertised by both VLT nodes are identical for a given EVI or MAC address, BGP always prefers the local route and will not download the duplicate route received from the VLT peer to EVPN.

In case of race conditions, the EVPN echo route from VLT peer can be received before the local route is available. These peer EVPN routes are differentiated using their Next-hop VTEP IP, which is the same as their own local NVE source IP and ignored by the EVPN layer.