Dynamic area filtering for link-state routing protocols

摘要

In general, techniques are described for dynamically filtering, at area border routers (ABRs) of a multi-area autonomous system, routes to destinations external to an area by advertising to routers of the area only those routes associated with a destination address requested by at least one router of the area. In one example, a method includes receiving, by an ABR that borders a backbone area and a non-backbone area of a multi-area autonomous system that employs a hierarchical link state routing protocol to administratively group routers of the autonomous system into areas, a request message from the non-backbone area that requests the ABR to provide routing information associated with a service endpoint identifier (SEI) to the non-backbone area. The request message specifies the SEI. The method also includes sending, in response to receiving the request and by the ABR, the routing information associated with the SEI to the non-backbone area.

主权项

1. A method comprising:
receiving, by a router, a service endpoint identifier for a remote router that provides reachability to a service, wherein the router is logically located in a non-backbone area of a multi-area autonomous system that employs a hierarchical link state routing protocol to administratively group routers of the autonomous system into areas, and wherein the remote router is logically located external to the non-backbone area; sending, by the router to the non-backbone area, a request message that requests an area border router for the non-backbone area to reconfigure a filter associated with the link state routing protocol to cause the area border router to flood, in accordance with the link state routing protocol, link state information associated with the service endpoint identifier to the non-backbone area; and receiving, by the router, the link state information flooded into the non-backbone area by the area border router after reconfiguring the filter, the link state information being usable for determining a path to the remote router.