Cisco Systems OL-4580-01 Configuring Equal-Cost Routes, Configuring Summarized Routes at an ABR

Chapter 3 Configuring Open Shortest Path First (OSPF)

Configuring OSPF on the CSS

To propagate summary LSAs in the stub area, include the send-summariesoption. For example:

(config)# ospf area 0.0.0.1 stub send-summaries

Removing an Area

To remove an OSPF area, disable OSPF, then use the no form of the ospf area command. For example:

(config)# no ospf enable

(config)# no ospf area 0.0.0.1

Configuring Equal-Cost Routes

By default, the OSPF CSS is configured to use 15 equal-cost routes. Use the ospf equal-costcommand to change the number of routes. Enter a number from 1 to 15.

To configure 10 equal-cost routes for use by the CSS, enter:

(config)# ospf equal-cost 10

To reset the equal-cost routes to its default value of 15, enter:

(config)# no ospf equal-cost

Configuring Summarized Routes at an ABR

If the CSS is an ABR, you can configure it to advertise a single summary route or network ranges that cover all the individual networks within the specified range. This summarization helps control routing table sizes and prevents the constant changing of routes whenever an interface within an area comes online or goes offline. These route changes do not cause route changes in backbone ABRs and other area routers.

Use the ospf range command to specify the IP address range to summarize routes at the ABR. This summarization applies to inter-area paths that are paths to destinations in other OSPF areas. You can also determine whether you want to advertise this range. Disable OSPF before you enter the ospf range command.

	Cisco Content Services Switch Routing and Bridging Configuration Guide
3-14	OL-4580-01