Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 1162

When you import routes into VRF-blue using the route-map import_ospf_protocol, only OSPF routes are imported into VRF-blue. Even though VRF-red has leaked both OSPF as well as BGP routes to be shared with other VRFs, this command imports only OSPF routes into VRF-blue. 9 Configure the import target in the source VRF for reverse communnication with the destination VRF.ip route-import 2:2 The show run output for the above configuration is as follows: ip vrf vrf-Red ip route-export 1:1 export_ospfbgp_protocol ip route-import 2:2 ! this action exports only the OSPF and BGP routes to other VRFs ! ip vrf vrf-Blue ip route-export 2:2 ip route-import 1:1 import_ospf_protocol !this action accepts only OSPF routes from VRF-red even though both OSPF as well as BGP routes are shared The show VRF commands displays the following output: Important Points to Remember • Only Active routes are eligible for leaking. For example, if VRF-A has two routes from BGP and OSPF, in which the BGP route is not active. In this scenario, the OSPF route takes precedence over BGP. Even though the Target VRF-B has specified filtering options to match BGP, the BGP route is not leaked as that route is not active in the Source VRF. • The export-target and import-target support only the match protocol and match prefix-list options. Other options that are configured in the route-maps are ignored. • You can expose a unique set of routes from the Source VRF for Leaking to other VRFs. For example, in VRF-red there is no option for exporting one set of routes (for example, OSPF) to VRF- blue and another set of routes (for example, BGP routes) to some other VRF. Similarly, when two VRFs leak or export routes, there is no option to discretely filter leaked routes from each source VRF. Meaning, you cannot import one set of routes from VRF-red and another set of routes from VRF-blue. Configuring Route Leaking without Filtering Criteria You can use the ip route-export tag command to export all the IPv4 routes corresponding to a source VRF. For leaking IPv6 routes, use the ipv6 route-export tag command. This action exposes source VRF's routes (IPv4 or IPv6 depending on the command that you use) to various other VRFs. The destinations or target VRFs then import these IPv4 or IPv6 routes using the ip route-import tag or the ipv6 routeimport tag command respectively. NOTE: In Dell Networking OS, you can configure at most one route-export per VRF as only one set of routes can be exposed for leaking. However, you can configure multiple route-import targets because a VRF can accept routes from multiple VRFs. After the target VRF learns routes that are leaked by the source VRF, the source VRF in turn can leak the export target corresponding to the destination VRFs that have imported its routes. The source VRF learns the export target corresponding to the destinations VRF using the ip route-import tag or ipv6 routeimport tag command. This mechanism enables reverse communication between destination VRF and the source VRF. Virtual Routing and Forwarding (VRF) 1162