SMC Networks SMC8612XL3 F 1.0.1.3 manual 295, These nodes, this wastes a lot of bandwidth

IP ROUTING

Console#show ip ospf3-170

Routing Process with ID 192.168.1.253

Supports only single TOS(TOS0) route

Number of area in this router is 3

Area 0.0.0.0 (BACKBONE)

Number of interfaces in this area is 1

SPF algorithm executed 40 times

Area 0.0.0.2 (STUB)

Number of interfaces in this area is 1

SPF algorithm executed 8 times

Area 0.0.0.3 (NSSA)

Number of interfaces in this area is 1

SPF algorithm executed 40 times

Console#

Configuring Area Ranges (Route Summarization for ABRs)

An OSPF area can include a large number of
nodes. If the Area Border Router (ABR) has
to advertise route information for each of	area			area
			ABR
these nodes, this wastes a lot of bandwidth
		summary
and processor time. Instead, you can			route

configure an ABR to advertise a single summary route that covers all the individual networks within its area. When using route summaries, local changes do not have to be propagated to other area routers. This allows OSPF to be easily scaled for larger networks, and provides a more stable network topology.

Command Usage

•Use the Area Range Configuration page to summarize the routes for an area. The summary route for an area is defined by an IP address and network mask. You therefore need to structure each area with a contiguous set of addresses so that all routes in the area fall within an easily specified range. This router also supports Variable Length Subnet Masks (VLSMs), so you can summarize an address range on any bit boundary in a network address.

•To summarize the external LSAs imported into your autonomous system (i.e., local routing domain), use the Summary Address Configuration screen (page 3-308).

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