Patent ID: 8037167

Claim:
A method for counting hosts behind a network address translator in a network using a network device that is not behind the network address translator and using a protocol defining packets with identifiers, comprising: reading a plurality of the identifiers that each include an internet protocol identification field read from an internet protocol header of a packet of a plurality of the packets transmitted from the network address translator, wherein the internet protocol identification field is adapted for fragment reassembly and is not an address; forming a plurality of subsets of the packets based on the identifiers; automatically adding packets having an internet protocol identification value of zero to a nonmatching subset selected from the plurality of subsets of the packets; counting the plurality of subsets of the packets to determine a count of the plurality of subsets of the packets, wherein the plurality of subsets of the packets includes the nonmatching subset; and reporting a determined count of the hosts behind the network address translator, wherein the determined count of the hosts is the count of the plurality of subsets of packets.