Methods and associated structures for limiting the number of sessions presently active between a server process and client processes distributed over a number of computing devices on a network. The methods and associated structures serve to reduce resource hogging by a particular computing device on a network and thereby reduce opportunities for denial of service attacks on the security of a server node. The server process maintains a session log to record each presently active session between the server process and a computing node identified by a source identifier provided by the client with the establishment and termination of each session. When the number of such active sessions for a particular source identity exceeds the predetermined threshold further requests to establish new sessions associated with that same source identity are rejected by the server process. One useful application of the present invention is in Internet FTP servers to log and track utilization of the server resources by the IP address of the computing device that initiates each FTP session.