Implementing IS-IS on Cisco IOS XR Software
How to Implement IS-IS on CiscoIOSXR Software
RC-92
Cisco IOS XR Routing Configuration Guide
DETAILED STEPS
Command or Action Purpose
Step1 configure
Example:
RP/0/RP0/CPU0:router# configure
Enters global configuration mode.
Step2 router isis
instance-id
Example:
RP/0/RP0/CPU0:router(config)# router isis isp
Enables IS-IS routing for the specified routing instance, and
places the router in router configuration mode.
•By default, all IS-IS instances are automatically
Level1 and Level 2. You can change the level of
routing to be performed by a particular routing instance
using the is-type router configuration command.
Step3 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 yo u are
configuring multi-instance IS-IS. You can specify a
name for a NET and for an address.
•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.
Step4 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 Level2 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 Level2 adjacencies are established. The router acts
as a border router between the Level 2 backbone and its
Level1 area.