346 CHAPTER 32: I NTEGRATED IS-IS CONFIGURATIONBy default, the interface priority is 64. If the level-1 or level-2 is not specified, itdefaults to setting the priority of Level-1.Setting Router Type Based upon the position of the router, the levels can be divided into Level-1(intra-domain router), Level-2 (inter-domain router) and Level-1-2 (that is,intra-domain router as well as inter-domain router).Perform the following configuration in IS-IS view.By default, the router type is level-1-2.Setting Interface CircuitLevelPerform the following configuration in Interface view.n Only when the router to which the interface belongs is of Level-1-2 type, is themodification to the interface circuit level meaningful. Otherwise, the type of therouter determines the level of adjacency relation.You can set the circuit level to limit what adjacency can be established for theinterface. For example, Level-1 interface can only have Level-1 adjacency. Level-2interface can only have Level-2 adjacency. For the Level-1-2 router, you canconfigure some interfaces to Level-2 to prevent transmitting Level-1 Hello packetsto Level-2 backbone so as to save the bandwidth. However, Level-1 and Level-2use the same kind of Hello packet over the p2p link, and therefore such setting isunnecessary in this case.By default, the circuit-level on the interface is level-1-2.Configuring IS-IS toImport Routes of OtherProtocolsFor IS-IS, the routes discovered by other routing protocols are processed as theroutes outside the routing domain. When importing the routes of other protocols,you can specify the default cost for them.When IS-IS imports routes, you can also specify to import the routes to Level-1,Level-2 or Level-1-2.Table 311 Set priority for DIS electionOperation CommandSet the priorities for DIS election on theinterface isis dis-priority value [ level-1 | level-2 ]Restore the default priorities for DIS electionon the interface undo isis dis-priority [ level-1 | level-2 ]Table 312 Set the router typeOperation CommandSet the router type is-level { level-1 | level-1-2 | level-2 }Restore the default router type undo is-levelTable 313 Set the interface circuit levelOperation CommandSet the interface circuit level isis circuit-level [ level-1 | level-1-2 | level-2 ]Restore the default interface circuit level undo isis circuit-level
