The present invention is related to a technology for grasping the number of a plurality of terminals of a client using a Cookie in a private network in which plural terminals are shared by redirecting a session which is to be connected to a Web by analyzing a TCP/IP packet, detecting the accurate number of a plurality of terminals of a client using an Internet, and making the accurate number as a DB, and selectively permitting or blocking a connection to Internet according to TCP/IP by using the Cookie pool information of a DB type and JOB when the users configuring and using a private network connect to the Internet at the same time.