Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 971

The following example relates to the configuration shown in Figure1 and Figure 2. Router 1 Router 2 The following shows the output of the show commands on Router 1. Router 1 The following shows the output of the show commands on Router 2. Router 2 Dynamic Route Leaking Route Leaking is a powerful feature that enables communication between isolated (virtual) routing domains by segregating and sharing a set of services such as VOIP, Video, and so on that are available on one routing domain with other virtual domains. Inter-VRF Route Leaking enables a VRF to leak or export routes that are present in its RTM to one or more VRFs. Previous FTOS releases support static route leaking, which enables route leaking through static commands. Dynamic Route Leaking, introduced in the 9.7(0.0) release, enables a source VRF to share both its connected routes as well as dynamically learnt routes from various protocols, such as ISIS, OSPF, BGP, and so on, with other default or non-default VRFs. You can also leak global routes to be made available to VRFs. As the global RTM usually contains a large pool of routes, when the destination VRF imports global routes, these routes will be duplicated into the VRF's RTM. As a result, it is mandatory to use route-maps to filter out leaked routes while sharing global routes with VRFs. Configuring Route Leaking with Filtering When you initalize route leaking from one VRF to another, all the routes are exposed to the target VRF. If the size of the source VRF's RTM is considerablly large, an import operation results in the duplication of the target VRF's RTM with the source RTM entries. To mitigate this issue, you can use route-maps to filter the routes that are exported and imported into the route targets based on certain matching criteria. These match criteria include, prefix matches and portocol matches. You can use the match source-protocol or match ip-address commands to specify matching criteria for importing or exporting routes between VRFs. NOTE: You must use the match source-protocol or match ip-address commands in conjunction with the route-map command to be able to define the match criteria for route leaking. Consider a scenario where you have created two VRF tables VRF-red and VRF-blue. VRF-red exports routes with the export_ospfbgp_protocol route-map to VRF-blue. VRF-blue imports these routes into its RTM. For leaking these routes from VRF-red to VRF-blue, you can use the ip route-export route-map command on VRF-red (source VRF, that is exporting the routes); you must also specify a match criteria for these routes using the match source-protocol command. When you leak these routes into VRF-blue, only the routes (OSPF and BGP) that satisfy the matching criteria defined in route-map export_ospfbgp_protocol are exposed to VRF-blue. Virtual Routing and Forwarding (VRF) 971