fabric-esi

ESI value

Skip installing EVPN Type 2 MAC-IP host routes for the specified interconnect ESI (I-ESI) value.

Include this option with other options and routing policies on access layer devices to manage remote host routing in very large campus EVPN-VXLAN networks that use EVPN Type 2 and Type 5 route stitching with Data Center Interconnect (DCI). With this host route management method, the access layer devices install only EVPN Type 5 subnet routes advertised from the distribution layer. Because the access layer devices use the EVPN Type 5 subnet routes, they don't need to install EVPN Type 5 remote host routes (IPv4 /32 or IPv6 /128 routes).

However, due to EVPN Type 2 and Type 5 coexistence rules, the access layer devices install Type 2 MAC-IP routes if Type 5 routes for the same destinations are not present. When you configure this option, the devices also avoids installing Type 2 destination routes even when equivalent Type 5 routes are not installed.

You configure this option on the access layer devices that act as peer DCI stitching devices as follows:

• Specify the I-ESI for the interconnection device peers as the fabric-esi esi value.

• Include a BGP protocol import policy that blocks importing EVPN Type 5 host routes (IPv4 /32 routes or IPv6 /128 routes).

See EVPN Host Route Management for Large-Scale Stretched Campus Networks for details. See also the interface-routes import-primary policy option and associated policy statement, which ensures that access layer and distribution layer devices prefer EVPN Type 5 subnet routes over direct routes for the same prefix.