Introducing Aggregated Routes into NLSP

Aggregated routes are introduced into NLSP in the same way that external RIP routes are introduced. There are two methods of introducing aggregated routes into NLSP:

• Aggregated routes are introduced through static configurations. If an aggregated route is configured for a static routing link, the configured aggregated route is reported into the NLSP area as soon as IPXRTR binds to the interface.
• Aggregated routes are learned from RIP. An address summary can be configured for a link, but unless at least one address matches the address summary, as learned through RIP, the summary is not reported.

For example, if a router is configured with address summaries 572* and 5729* on a link running RIP and learns from that link that the destination 57285489 is reachable and that no other matching destinations are learned, then the router reports the aggregated route 572* to the NLSP area. The asterisk represents a wildcard character. If the router learns that destination 57298381 is reachable, then only 5729* is reported to the NLSP area. If both 57298381 and 57212376 are reachable, then the router reports both 572* and 5729* to the NLSP area.

Routers always report aggregated routes with the longest match. For example, if a router is configured with address summaries C9* and C91* and learns that the destination C9123456 is reachable, then the router reports only the aggregated route C91*.