Communication connection method for connecting server computer to client computer via network, comprises storing group identification information items for identifying groups, in relation to information indicating number of connection request packets uniquely and secretly allocated to each group of groups, each group including users allowed to access server computer, counting connection request packets received from client computer within preset period to obtain counted number, determining whether information corresponds to counted number, acquiring one group of groups to which connection request packets corresponding to counted number are allocated, if information corresponds to counted number, determining whether resources of server computer are allocated to group indicated by acquired group identification item, generating connection request acknowledgement packet in response to at least one of received connection request packets, and transmitting generated connection request acknowledgement packet to network.