Users Guide

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.
While importing these routes into VRF-blue, you can further specify match conditions at the import end
to define the filtering criteria based on which the routes are imported into VRF-blue. You can define a
route-map import_ospf_protocol and then specify the match criteria as OSPF using the match source-
protocol ospf command.
Virtual Routing and Forwarding (VRF)
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