Patent ID: 8054804

Claim:
A network server for provisioning at least one Local Area Network (LAN), the network server comprising: a client entry store configured to store records representing a user device connecting to the LAN provisioned by the network server as a roaming visitor of the LAN to gain temporal access to an outside network through the LAN, the LAN having multiple routing realms, the client entry store further configured to store records representing one or more routing realm top-level devices provided on a top level of each routing realm; a packet driver module configured to inspect packets arriving from and directed to the user device, and to interact with the client entry store to process the packets; and a Dynamic Host Configuration Protocol (DHCP) request handler configured to examine data in DHCP packets received from the user device and the records in the client entry store, wherein at least one of the packet driver module and the DHCP request handler detects roaming between routing realms by the user device based on the data of the packets and the records in the client entry store, the DHCP request handler comprises: a DHCP packet data handling unit configured to obtain packet data relating to addresses included in a DHCP request packet received from the user device; a client entry store record handling unit configured to access and manipulate the address data in the records in the client entry store; an address data comparator configured to compare the packet data of the DHCP request packet and the address data of the records in the client entry store; and a routing realm traversal handling unit configured to determine traversal of routing realms by the user device when a data comparison result meets a predetermined condition, in response to the detection of roaming by the user device, the routing realm traversal handling unit of the DHCP request handler assigns to the user device a new Internet Protocol (IP) address suitable to a routing realm top-level device of a routing realm into which the user device has roamed, and the DHCP request handler provides the new IP address to the user device, and when the new IP address is assigned, the client entry store record handling unit of the DHCP request handier manipulates the address data in the records in the client entry store so that the records representing the user device include a new record having the new IP address and a device address of the routing realm top-level device through which the user device is currently connecting to the network server.