Specifications
Implementing IS-IS on Cisco IOS XR Software
How to Implement IS-IS on Cisco IOS XR Software
RC-181
Cisco IOS XR Routing Configuration Guide
Step 3
net 
network-entity-title
Example:
RP/0/RP0/CPU0:router(config-isis)# net 
47.0004.004d.0001.0001.0c11.1110.00
Configures network entity titles (NETs) for the routing 
instance. 
• Specify a NET for each routing instance if you are 
configuring multi-instance IS-IS. 
• This example configures a router with area ID 
47.0004.004d.0001 and system ID 0001.0c11.1110.00.
• To specify more than one area address, specify 
additional NETs. Although the area address portion of 
the NET differs, the systemID portion of the NET must 
match exactly for all of the configured items.
Step 4
is-type {level-1 | level-1-2 | level-2-only}
Example:
RP/0/RP0/CPU0:router(config-isis)# is-type 
level-2-only
(Optional) Configures the system type (area or backbone 
router).
• By default, every IS-IS instance acts as a level-1-2 
router.
• The level-1 keyword configures the software to perform 
Level 1 (intra-area) routing only. Only Level 1 
adjacencies are established. The software learns about 
destinations inside its area only. Any packets 
containing destinations outside the area are sent to the 
nearest level-1-2 router in the area.
• The level-2-only keyword configures the software to 
perform Level 2 (backbone) routing only, and the router 
establishes only Level 2 adjacencies, either with other 
Level 2-only routers or with level-1-2 routers. 
• The level-1-2 keyword configures the software to 
perform both Level 1 and Level 2 routing. Both Level 1 
and Level 2 adjacencies are established. The router acts 
as a border router between the Level 2 backbone and its 
Level 1 area.
Command or Action Purpose










