PORT ACCESS CONTROL SYSTEM, FTP DATA CONNECTION ELABORATION METHOD, AND FIRE-WALL

摘要

PROBLEM TO BE SOLVED: To provide a port access control system that efficiently performs the elaboration of a data connection or the like in an FTP file transmission via a fire-wall and to provide an FTP data connection elaboration method and the fire-wall. SOLUTION: An FTP client 3 requests a firewall 7 to permit an access to a data connection port 3b dynamically assigned from an operating system from an external network to elaborate a data connection 6 between FTP servers 4. When the data connection 6 is open, the fire-wall 7 cancels the access permission to the port 3b.