sending an inter-proxy request message to an IP address identifying an inter-proxy multicast group to which the first access point belongs, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested, wherein a plurality of access points are members of the inter-proxy multicast group, thereby enabling the inter-proxy request message to be received by the plurality of access points; and

receiving an inter-proxy reply message from a second access point in the plurality of access points in the inter-proxy multicast group, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information, wherein the IP address does not uniquely identify the second access point, wherein the registration request is a Mobile IP registration request, wherein the second access point is not a Home Agent of the node.