Patent ID: 8606887

Claim:
A method for verification of a DHCPRELEASE message comprising: receiving the DHCPRELEASE message at a server via a tunnel; determining if there is a secure link between a client sending the DHCPRELEASE message and the server receiving the DHCPRELEASE message; assuming the client is an authorized client if there is the secure link between the client and the server; extracting the Internet Protocol (IP) address from a ciaddr field of the DHCPRELEASE message; determining a tunnel-associated IP address, wherein the tunnel-associated IP address is an IP address associated with the tunnel from which the server receives the DHCPRELEASE message; comparing the IP address and the tunnel-associated IP address to determine if there is a match; and releasing the IP address if there is a match or discarding the DHCPRELEASE message if there is no match.