Enable the IS-IS protocol on a device, as described in To enable IS-IS on a routing instance .

In the navigation tree Routing view, expand Network→NE→Routing Instance→ISIS Instances→ISIS Instance.

Right-click on the ISIS Instance object and choose Add NET Address. The Area ID (Create) form opens.

Configure the Area ID parameter.

Note: The Area ID forms part of the NET address. NET addresses are built from some non-configurable elements, including the device system ID and the network selector ID.The NET address is exchanged in hello and link-state PDUs. Level 1 interfaces must have at least one area ID in common. Level 2 interfaces can have different area IDs. If all of the interfaces have different area IDs, they are considered level 2 interfaces only.

Save your changes and close the form.

End of steps