Intermediate System to Intermediate System | 513Configuration Task List for IS-ISThe following list includes the configuration tasks for IS-IS:• Enable IS-IS on page 513• Configure Multi-Topology IS-IS (MT IS-IS) on page 516• Configure IS-IS Graceful Restart on page 517• Change LSP attributes on page 520• Configure IS-IS metric style and cost on page 521• Change the IS-type on page 523• Control routing updates on page 524• Configure authentication passwords on page 529• Set the overload bit on page 529• Debug IS-IS on page 530Enable IS-ISBy default, IS-IS is not enabled.The system supports one instance of IS-IS. To enable IS-IS globally, create an IS-IS routing process andassign a NET address. To exchange protocol information with neighbors, enable IS-IS on an interface,instead of on a network as with other routing protocols.In IS-IS, neighbors form adjacencies only when they are same IS type. For example, a Level 1 router neverforms an adjacency with a Level 2 router. A Level 1-2 router will form Level 1 adjacencies with aneighboring Level 1 router and will form Level 2 adjacencies with a neighboring Level 2 router.Use these commands in the following sequence to configure IS-IS globally.Note: Even though you enable IS-IS globally, you must enable the IS-IS process on an interface for theIS-IS process to exchange protocol information and form adjacencies.Step Task Command Syntax Command Mode1 Create an IS-IS routing process.• tag is optional and identifies the name of the IS-ISprocess.router isis [tag] CONFIGURATION2 Configure an IS-IS network entity title (NET) for a routingprocess.Specify the area address and system ID for an IS-IS routingprocess. The last byte must be 00.Refer to IS-IS Addressing for more information onconfiguring a NET.netnetwork-entity-titleROUTER ISIS
