Patent ID: 8477774

Claim:
A method for detecting a host included in a network, comprising: extracting an Internet Protocol Identifier value IPID1 from an obtained data packet; searching in a record table containing a correspondence relationship between an Internet Protocol Identifier value and a terminal serial number to determine whether the record table contains an adjacent Internet Protocol Identifier value IPID2 smaller than the extracted Internet Protocol Identifier value IPID1; modifying the adjacent Internet Protocol Identifier value IPID2 to be the Internet Protocol Identifier value IPID1 if the record table contains the adjacent Internet Protocol Identifier value IPID2 that is smaller than the extracted Internet Protocol Identifier value IPID1; adding a new record of the Internet Protocol Identifier value IPID1 and the corresponding terminal serial number into the record table otherwise; and calculating a number of terminal serial numbers in the record table and outputting the number of terminal serial numbers as a number of hosts.