Patent ID: 7260075

Claim:
A fast Duplicate Address Detection (DAD) Entity that can be implemented either as part of the access router or within the distribution system that includes multiple Access Points and multiple mobile nodes associated therewith, comprising: a memory unit for storing an address table recording information including IP addresses of the multiple mobile nodes; an interface unit for receiving Neighbor Solicitation messages that includes the IP address of the mobile node newly associated with the distribution system; a record unit for extracting the IP address of the mobile node from the Neighbor Solicitation messages, and records the IP address in the address table; a search unit for searching the IP addresses of the multiple mobile nodes stored in the address table; a decision unit for comparing the IP address of the new mobile node with the IP addresses of the multiple mobile nodes already configured on the sub-network, and decides whether there exists a same IP address; and a control unit for generating a response message notifying that the IP address of the new mobile node is unique on this sub-network and can be used as new Care-of Address (CoA), and sending this response message to the new mobile node through the interface unit, if there does not exist the same IP address as a result of the decision of the decision unit.