17.3. xinetd

The xinetd daemon is a TCP wrapped super service which controls access to a subset of popular network services including FTP, IMAP, and Telnet. It also provides service-specific configuration options for access control, enhanced logging, binding, redirection, and resource utilization control.
When a client host attempts to connect to a network service controlled by xinetd, the super service receives the request and checks for any TCP wrappers access control rules. If access is allowed, xinetd verifies that the connection is allowed under its own access rules for that service and that the service is not consuming more than its alloted amount of resources or is in breach of any defined rules. It then starts an instance of the requested service and passes control of the connection to it. Once the connection is established, xinetd does not interfere further with communication between the client host and the server.