Cisco Systems 78-11741-02 manual Miscellaneous IS-IS Parameters Configuration Task List, IPC-284

Configuring Integrated IS-IS

Miscellaneous IS-IS Parameters Configuration Task List

Miscellaneous IS-IS Parameters Configuration Task List

The following tasks differ from the preceding interface-specific IS-IS tasks because they configure IS-IS itself, rather than the interface.

To configure optional IS-IS parameters as described in the following sections:

•Generating a Default Route (Required)

•Specifying the System Type (Optional)

•Configuring IS-IS Authentication Passwords (Optional)

•Summarizing Address Ranges (Optional)

•Setting the Overload Bit (Optional)

•Changing the Routing Level for an Area (Optional)

•Tuning LSP Interval and Lifetime (Optional)

•Customizing IS-IS Throttling of LSP Generation, SPF Calculation, and PRC (Optional)

•Modifying the Output of show Commands (Optional)

Generating a Default Route

You can force a default route into an IS-IS routing domain. Whenever you specifically configure redistribution of routes into an IS-IS routing domain, the Cisco IOS software does not, by default, redistribute the default route into the IS-IS routing domain. The following command generates a default route into IS-IS, which can be controlled by a route map. You can use the route map to identify the level into which the default route is to be announced, and you can specify other filtering options configurable under a route map. You can use a route map to conditionally advertise the default route, depending on the existence of another route in the routing table of the router.

To generate a default route, use the following command in router configuration mode:

Command	Purpose
Router(config-router)#default-information originate	Forces a default route into the IS-IS routing domain.
[route-map map-name]

See also the discussion of redistribution of routes in the “Configuring IP Routing Protocol-Independent Features” chapter of this document.

Specifying the System Type

You can configure the router to act as a Level 1 (intra-area) router, as both a Level 1 router and a Level 2 (interarea) router, or as an interarea router only.

To specify router level support, use the following command in router configuration mode:

Command		Purpose
Router(config-router)# is-type{level-1 level-1-2		Configures the system type (area or backbone router).
level-2-only}
	Cisco IOS IP Configuration Guide

IPC-284