Inetd, also known as the Internet superserver, is a program on many Unix-like computer operating systems that manages Internet services. The newer version of it is known as xinetd. Both components start their respective services like telnet, FTP, or POP3 when a network request is received. After the service is provided, inetd or xinetd then dismiss the triggered process until a new connection is made. Thus, it ensures that system resources are used efficiently.
Inetd (xinetd) Examples
1. FTP Service Management Example
Inetd or xinetd managing an FTP service is a prime example of how these superservers operate. FTP, standing for File Transfer Protocol, is a standard network protocol used for the transfer of computer files between a client and a server on a computer network.
Stay One Step Ahead of Cyber Threats
Here’s how it works: when an individual or an application wishes to transfer files using the FTP protocol, inetd or xinetd maintains a constant watch, listening for such requests. Upon receiving the request, inetd or xinetd goes into action and starts the FTP service to facilitate the file transfer.
This process allows the FTP service to run seamlessly and effectively, transferring the necessary files. However, once the transfer is completed, and the service’s need is over, inetd or xinetd then pauses or dismisses this service. This feature helps avoid the continuous running of the FTP service when it’s not needed, conserving system resources. The service waits to be triggered again by a new connection or a new request, making the system more efficient.
2. Telnet Service Management Example
Inetd or xinetd efficiently handles the Telnet service, which provides interactive communication between two computer systems. It’s a command-line tool used mainly by administrators to gain remote access and control of a computer system.
The inetd or xinetd, acts like a switchboard operator, identifying when a person or a system tries to initiate a telnet session. After recognizing the incoming request, it starts up the telnet service.
The user can then remotely access the command line of the target computer, execute commands, and manage the system. After the user has accomplished their tasks and exits the telnet session, the superserver, whether inetd or xinetd, shuts down the telnet service. This step ensures the service doesn’t continue to use system resources when it’s not required, improving system efficiency. The management of the Telnet service by inetd or xinetd signifies the utility and efficiency of these superservers in a UNIX-like operating system.
3. POP3 Email Server Management Example
The management of an email server using the Post Office Protocol version 3 (POP3) is another example where inetd or xinetd plays a significant role. POP3 is mostly used by email clients to retrieve emails from a mail server.
In such a scenario, inetd or xinetd acts as the listener for a POP3 request. When an email client sets out to retrieve email from the remote server, the request does not go unnoticed—inetd or xinetd detects it. Subsequently, it powers up the POP3 service, enabling smooth email retrieval.
Once the emails are successfully fetched and the task is accomplished, inetd or xinetd does not let the POP3 service keep consuming system resources unnecessarily. It shuts down the service. Now the POP3 service will only be activated when another incoming request is detected, ensuring the effective use of system resources by not running services when they’re not required, and thereby illustrating the efficiency of inetd or xinetd.
Conclusion
It’s clear that inetd and xinetd, as superservers, greatly contribute to enhancing the system efficiency in Unix-like operating systems. By managing services like FTP, Telnet, and POP3, this useful tool optimizes resource consumption, only activating services as needed and effectively annexing them when their tasks are done.
Key Takeaways
- Inetd and its newer version, xinetd, are superservers that manage internet services in Unix-like operating systems.
- These superservers only activate services when they receive a network request, thereby optimizing system resources.
- Examples of inetd’s work include managing FTP for file transfers, Telnet for remote access, and POP3 for managing email servers.
- Inetd and xinetd greatly enhance system efficiency by starting and stopping services as needed.
- The superserver concept of inetd and xinetd helps keep unused services from consuming system resources unnecessarily.
Related Questions
1. Can inetd or xinetd be used in any operating system?
Inetd and xinetd are primarily for Unix-like operating systems, which include Linux, BSD, and others of the like. For Windows, there are similar services, but inetd and xinetd are not suitable.
2. How do inetd and xinetd conserve system resources?
Inetd and xinetd conserve system resources by only running services when they receive a network request, and then stopping them when not in use. This strategy prevents services from running continuously and consuming resources when they aren’t needed.
3. What is the main difference between inetd and xinetd?
Inetd is the older version, while xinetd is an extended and more secure version. Xinetd also offers better logging and binding capabilities and addresses some of the security concerns of inetd.
4. Are there alternatives to inetd and xinetd?
Yes, there are alternatives to inetd and xinetd. These include tools like systemd and rlinetd for Linux, which can provide similar functionality.
5. How does the system know to use inetd or xinetd?
The system knows to use inetd or xinetd based on the configuration files for each service. These files tell the system where to find the network service, what procedures to run when a network request is received, and additional settings to optimize efficiency.
"Amateurs hack systems, professionals hack people."
-- Bruce Schneier, a renown computer security professional
