To enable IS-IS, you should create an IS-IS process and activate it on the interfaces that may be associate with other devices.
isis [ process-id ]
process-id identifies an IS-IS process. If process-id is not set, the system uses process 1 by default. To associate the IS-IS process to a VPN instance, you can run the isis [ process-id ] [ vpn-instance vpn-instance-name ] command.
The VPN instance name indicates a common VPN or the VPN created for a virtual system.
When you configure an IS-IS route for a virtual system, the IS-IS process must be bound to the VPN instance with the same name as the virtual system.