Abstract: In general, this disclosure describes network security techniques that may accommodate legitimate movement of a subscriber device while preventing MAC collisions that may result from configuration errors or MAC spoofing attempts. MAC spoofing may result in packets directed to one subscriber device being sent instead to another subscriber device. By modifying an access node or a Dynamic Host Configuration Protocol (DHCP) server to allow only authorized subscriber devices on the access network, layer two collisions (“MAC collisions”) may be prevented.

Abstract: In general, this disclosure describes network security techniques that may accommodate legitimate movement of a subscriber device while preventing MAC collisions that may result from configuration errors or MAC spoofing attempts. MAC spoofing may result in packets directed to one subscriber device being sent instead to another subscriber device. By modifying an access node or a Dynamic Host Configuration Protocol (DHCP) server to allow only authorized subscriber devices on the access network, layer two collisions (“MAC collisions”) may be prevented.

Abstract: In general, techniques are described for applying adaptive thresholds to multicast streams within computer networks. For example, an access node may implement the techniques to facilitate efficient delivery of multicast streams. The access node comprises an interface that couples to a subscriber network having a subscriber device. The access node also includes a control unit that determines a multicast stream count reflecting current delivery of multicast streams to the subscriber network and a threshold value based on historical multicast stream counts delivered to the subscriber. The interface receives a message requesting to join a multicast group in accordance with a multicast management protocol. In response to this message, the control unit determines a projected stream count based on the above current multicast count. The control unit then compares the projected stream count to the threshold value, and admits the subscriber device to the multicast group based on the comparison.