Patent ID: 7646786

Claim:
A system, comprising: a Cable Modem Termination System (CMTS) configured to operate between a data network and a cable network, the CMTS to communicate upstream traffic sent from a plurality of cable modems to the data network, to receive traffic from the data network for forwarding downstream to the cable modems, wherein the CMTS includes: a database containing addressing information for the cable modems; a communications link to allow the CMTS to communicate with the cable network; and circuitry configured to: receive a neighbor discovery message from a requesting one of the cable modems; identify an address corresponding to the received neighbor discovery message; compare the identified address to the database to determine whether the database includes a stored address corresponding to the identified address; forward the received neighbor discovery message if the corresponding stored address is absent from the database; and filter the received neighbor discovery message according to the comparison such that the neighbor discovery message is not forwarded to one of the other cable modems if the corresponding stored address is present in the database.