A home network system that makes it possible to build a network with assured security, wherein network users need not have security expertise. For access attempts offered from a home node 21-1 in a community area network 5-1 toward an outside public network 1 through a path N2, a security server 11-1 need not execute an authentication process. The home node 21-1 rejects access attempts directly transferred from the public network 1. The security server 11-1 executes the authentication process for an access attempt transferred from the public network 1 through a path N42. When the authentication is successful, connection of the access attempt to the home node 21-1 through a path N9 is permitted.