Patent ID: 7096273

Claim:
A method for a DHCP client to send a DHCP request to a DHCP server via a BOOTP Relay Agent, the DHCP client contained in a Mobile Host having a MAC address and having MAC layer connectivity with a foreign agent having a MAC address and a care of IP address, the BOOTP Relay Agent being coupled to a home agent having an address, the step comprising: A) sending a mobile IP Registration Request message and a Mobile IP Registration Reply message to establish a Mobile IP forward tunnel and a Mobile IP reverse tunnel, the Mobile IP Registration Request having a Mobile Host Identifier that is set to the MAC address of the Mobile Host, and the Mobile IP Registration Reply message having a Mobile Host Identifier that is set to the address of the Mobile Host, wherein the MAC address of the Mobile Host is used to identify mobility bindings for the Mobile Host; B) generating a DHCP request, the DHCP request having a protocol field, a source IP address and a giaddr field, the protocol field containing the MAC address of the Mobile Host, the source IP address is zero, and the giaddr field is zero; C) sending the DHCP request to the foreign agent; D) adding an encapsulation header by the foreign agent; E) sending the request to the home agent; F) removing the encapsulation header; and G) forwarding the request to a home subnet; H) generating a DHCP reply, the DHCP reply having a protocol field, the protocol field containing the MAC address of the Mobile Host; I) sending the DHCP reply across the home subnet to the home agent; J) adding an encapsulation header to the reply by the home agent; K) forwarding the reply to the foreign agent; L) removing the encapsulation header by the foreign agent; and M) forwarding the reply to the mobile host; wherein the DHCP client obtains an IP address from a DHCP server on the home subnet via the Mobile IP forward tunnel.