Users Guide

Route selection in the leaked VRF
● If a route is present in the local VRF and the same route is leaked from another VRF, OS10 prefers the route with the lowest
administrative distance.
● If a route is present in the local VRF and the same route is leaked from another VRF with the same administrative distance,
OS10 prefers the local route.
● When OS10 compares routes that are received from different sources, the software prefers routes with the lowest
administrative distance. If the administrative distance is the same, the software prefers the route with lowest metric value. If
the metric is also the same, the software prefers the local route, if available.
● If a VRF receives the same route from multiple VRFs, OS10 prefers the route that it received first. When the active route
fails, OS10 applies the route that it received after the first route to the routing table.
● If a VRF receives the same route from multiple VRFs with the same route target values, OS10 prefers the route that it
received first.
● If a VRF receives ECMP paths from another VRF, the VRF that receives the routes treats the routes as ECMP paths.
Redistribution of leaked routes
After you configure the system to leak routes from one VRF instance to another VRF instance, you can redistribute the leaked
routes to the same routing protocol. The following lists the commands that you use for redistribution of leaked routes:
● Redistribute leaked BGP routes to BGP—Use the redistribute imported-bgp-routes vrf vrf-name command.
● Redistribute leaked OSPF routes to OSPF—Use the redistribute imported-ospf-routes command.
● Redistribute leaked BGP EVPN routes to the BGP peer—Use the redistribute l2vpn evpn command.
Leak all IPv4 routes from one VRF to another VRF
Use the following procedure to export (leak) all IPv4 routes from all routing protocols from one VRF instance to another VRF
instance:
1. Enter the VRF from which you want to leak routes in CONFIGURATION mode.
ip vrf source-vrf-name
2. Export all routes that belong to one VRF instance in VRF-CONFIGURATION mode.
ip route-export route-target
3. Enter the VRF instance to which you want to leak routes in CONFIGURATION mode.
ip vrf destination-vrf-name
4. Import routes from another VRF instance in VRF-CONFIGURATION mode using the same route target.
ip route-import route-target
5. Export routes from the second VRF instance to the first VRF instance in VRF-CONFIGURATION mode using a different
route target.
ip route-import route-target
6. Import routes to the first VRF instance from the second VRF instance in VRF-CONFIGURATION mode using the same route
target that you use to export from the second VRF instance.
ip route-import route-target
Example - Leak all IPv4 routes
OS10(config)# ip vrf vrf1
OS10(conf-vrf)# ip route-export 1:1
OS10(conf-vrf)# ip route-import 2:2
OS10(conf-vrf)# exit
OS10(config)# ip vrf vrf2
OS10(conf-vrf)# ip route-import 1:1
Layer 3
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