Rules for establishing the adjacent type for the Type pairs of ISIS neighbor Routers

The rule that the type of the ISIS neighbor router forms the adjacent type. The two L1-only routers can form a L1 relationship only when their AID (Region ID) matches; www.2cto.com two L2-only routers can form a L2 relationship even if their AID is different; a L1-only router and a L1/L2 router can form a L1 relationship only when their AID matches; A L2-only router and an L1/L2 router can form a L2 adjacent relationship even if their AID is not at the same time;
Www.2cto.com if the AID of the two L1/L2 routers matches, they can form the relationship between the L1 and L2 routers at the same time. If the AID of the two L1/L2 routers does not match, they can only form the relationship between L1 and L2 types;