Inetd, or “internet daemon,” is a super-server daemon in many Unix-like operating systems that provides internet services. Its primary function is to listen to service requests at various ports. When a request is received at a given port, inetd launches the appropriate server program to handle the request. The server program then processes the request and terminates.
- FTP server: An FTP request received at port 21 will trigger inetd to launch the FTP server.
- Telnet server: A Telnet request received at port 23 will cause inetd to start the Telnet server.
Comparison to xinetd
Inetd and xinetd (“extended internet daemon”) provide similar functionality but differ in their capabilities. Xinetd offers enhanced security features like access control lists and logging, while inetd is simpler and lighter on system resources.
Advantages and disadvantages of inetd
- Saves system resources: Inetd saves system resources by starting internet services only when they’re needed.
- Simplicity: The configuration and use of inetd are straightforward.
- Limited security features: Inetd does not offer as many security features as xinetd.
- Lack of flexibility: Inetd does not support as many service options as its extended counterpart.
- Ensure that you are aware of the potential security risks associated with inetd and take measures to mitigate them.
- If you need more security or functionality, consider using xinetd or a standalone daemon instead of inetd.