 home address in the entry item; if the home address of the MN matches the source home address in the entry item, Step 000 is performed; otherwise, Step 000 is performed. In this step, the replaced source address of the data packet, i.e. the home address of the MN matches the source address in the entry item; if the home address of the MN matches the source address in the entry item, the matching is successful; otherwise, the matching is unsuccessful. Steps 000˜000: Query whether the data packet contains a 