In the Hub and Spoke networking, an access control device
is specified in the VPN, and users communicate with each other through
the access control device.
After associating an interface with a VPN instance, you can change the interface to a VPN interface. As a result, packets that pass through the interface are forwarded based on the forwarding information of the VPN instance, and such layer-3 attributes as IP address and routing protocol that are configured for the interface are deleted. These layer-3 attributes need to be re-configured if required.