There are no interfaces associated with IS-IS by default. An interface belongs to all areas configured on a router. Interfaces cannot belong to separate areas. There are no default interfaces applied to the router’s IS-IS instance. You must configure at least one IS-IS interface in order for IS-IS to work.
To enable IS-IS on an interface, first configure an IP interface in the config>router>interface context. Then, apply the interface in the config>router>isis>interface context.
You can configure both the level 1 parameters and the level 2 parameters on an interface. The level-capability value determines which level values are used.
The following example displays the modified interface parameters.
Example
config>router# isis
config>router>isis# level 1
config>router>isis>level# wide-metrics-only
config>router>isis>level# exit
config>router>isis# level 2
config>router>isis>level# wide-metrics-only
config>router>isis>level# exit
config>router>isis# interface ALA-1-2
config>router>isis>if# level-capability level-2
config>router>isis>if# exit
config>router>isis# interface ALA-1-3
config>router>isis>if# level-capability level-1
config>router>isis>if# interface-type point-to-point
config>router>isis>if# exit
The following example displays the global and interface-level configurations.
A:ALA-A>config>router>isis# info
----------------------------------------------
level-capability level-2
area-id 49.0180.0001
area-id 49.0180.0002
area-id 49.0180.0003
authentication-key "H5KBAWrAAQU" hash
authentication-type password
traffic-engineering
level 1
wide-metrics-only
exit
level 2
wide-metrics-only
exit
interface "system"
exit
interface "ALA-1-2"
level-capability level-2
exit
interface "ALA-1-3"
level-capability level-1
interface-type point-to-point
exit
interface "ALA-1-5"
level-capability level-1
interface-type point-to-point
exit
interface "to-103"
exit
----------------------------------------------
A:ALA-A>config>router>isis#