HP Routing Services -UX 11i v2 manual Point-to-Point Router Interface Example, Stub Areas

Configuring gated

Configuring the OSPF Protocol

Figure 3-8 shows an example of a router (A) that is connected to a non-broadcast, point-to-point network through interface 193.2.1.1.

Figure 3-8	Point-to-Point Router Interface Example
		Router
		A	193.2.1.1	193.2.1.2

Router

B

The following is an example of the interface definition in router A’s /etc/gated.conf file:

interface 193.2.1.1 nonbroadcast cost 5 { hellointerval 30 ; routerdeadinterval 30 ; retransmitinterval 30 ; pollinterval 30 ;

} ;

If the router A is connected to a multicast, point-to-point network, you must omit the nonbroadcast clause and the pollinterval statement.

Stub Areas

By default, AS external link advertisements (routes to destinations outside the AS) are propagated to every router in every area in the AS. You can configure certain OSPF areas as stub areas. AS external link advertisements are not flooded through stub areas. This reduces the size of the topology database that must be maintained by internal routers in the stub area and reduces the protocol traffic through the area. For example, if all the inter-area traffic for an area must go through a single router, then it is not necessary for all routers in the area to receive inter-area routing information.

An area border router advertises a default route in the stub area as the summary of all the IP destinations that are reachable outside the AS. Summary link advertisements (routes to destinations outside the area but within the AS) are still sent into the stub area.

The stub statement specifies that the area is a stub area. You can optionally define a cost clause to specify the cost associated with the default route that is advertised in the stub area.

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