You can set up your subscriber management environment to create dynamic IP subscriber interfaces in two situations—when a DHCP event occurs or when a packet is detected.
In the first case, the interface is created when an external DHCP server or the DHCP local server responds to a subscriber request. In the second case, the subscriber interface is created when the router receives a packet (the packet detect feature) with a source IP address that is not in the demultiplexer table. In this second case the primary IP interface must be in autoconfiguration mode.
Subscriber management uses the following process when validating the IP source address of the packet: