Patent ID: 7778203

Claim:
In a computer networking environment, a method performed by a DHCP server, the DHCP server comprising a device that assigns IP addresses to hosts, the method comprising: receiving a request packet comprising a DHCP request, the request packet including data representative of a MAC address of a requesting device that originated the DHCP request; in response to receiving the request packet, looking up whether port data is associated with the MAC address, and if so, using the port data to respond to the packet, where the looking up comprises transmitting MAC-port queries through multiple levels of switches until a second or higher level switch returns a port associated with the MAC address, the transmitting comprising sending a first MAC-port query to a first switch through which the DHCP server and the second or higher level switch exchange network packets, in response receiving from the first switch information identifying the second or higher level switch, and using the information identifying the second or higher level switch to transmit a second MAC-port query through the first switch to the second or higher-level switch which then returns the port associated with the MAC address; and using the returned port to assign an IP address to the MAC address.