Managing Linux® Systems with Webmin™ System Administration and Module Development

15.1. Introduction to Internet Services

Heavily used network services such as email, proxying, and web serving are handled by server processes that run continually and have their own complex configuration files and Webmin modules. However, there are other services like telnet, finger, and POP3 that do not need any configuration and do not need their own permanent server process. Instead, their servers are run when needed by a super server like inetd or xinetd which listens for network connections on multiple ports. Only when it receives a connection does it start the appropriate process to communicate with the client, which exits when the connection is closed. This saves memory by limiting the number of processes running at any one time, but ...