346 CHAPTER 29: IS-IS CONFIGURATIONConfiguring IS-IS RouteLeakingWith this feature enabled, the Level-1-2 router can advertise both Level-1 andLevel-2 area routing information to the Level-1 router.Follow these steps to configure IS-IS route leaking:n ■ If a filter policy is specified, only routes passing it can be advertised into Level-1area.■ You can specify a routing policy in the import-route isis level-2 into level-1command to filter routes from Level-2 to Level-1. Other routing policiesspecified for route reception and redistribution does not affect the routeleaking.Tuning andOptimizing IS-ISNetworkConfigurationPrerequisitesBefore the configuration, accomplish the following tasks first:■ Configure an IP address on each interface, and make sure all nodes arereachable.■ Configure basic IS-IS functionsConfiguring a DISPriority for an InterfaceOn an IS-IS broadcast network, a router should be selected as the DIS at a specificlevel, Level-1 or Level-2. You can specify a DIS priority at a level for an interface.The bigger the interface’s priority value, the more likelihood it becomes the DIS.Follow these steps to configure a DIS priority for an interface:Configure a filteringpolicy to filterredistributed routesfilter-policy { acl-number | ip-prefixip-prefix-name | route-policyroute-policy-name } export [ isisprocess-id | ospf process-id | ripprocess-id | bgp | direct | static]OptionalNot configured by defaultTo do… Use the command… RemarksTo do… Use the command… RemarksEnter system view system-view --Enter IS-IS view isis [ process-id ] --Enable IS-IS routeleakingimport-route isis level-2 into level-1[ filter-policy { acl-number | ip-prefixip-prefix-name | route-policyroute-policy-name } | tag tag ] *RequiredDisabled by defaultTo do… Use the command… RemarksEnter system view system-view --Enter interface view interface interface-typeinterface-number--Specify a DIS priority for theinterfaceisis dis-priority value[ level-1 | level-2 ]Optional64 by default
