What are Port Numbers?

There are many ways to transfer data and send messages on the internet. While transferring data or forwarding the message, different processes take place; the process in which the messages are forwarded to the server is identified from the port number. Many port numbers are used for networking, such as HTTP port, DNS port, and FTP port. 

The port number usually consists of 16-bit numbers. It plays a role in identifying and tracking the information, which helps determine the type of information and the devices used to transfer it. 

In simple words, there is a port on every networking device, and each port has a number that indicates the function it will perform and the protocol it will follow.

The port checker determines if a specific port is open and available for use on a target host. This is useful for network administrators, system administrators, and security professionals to check the status of various services running on a server, ensure that firewall configurations are correct, troubleshoot network connectivity issues, and perform security audits. By checking the status of a port, one can determine if a service is available and if it is, what type of service it is running.

Let’s move forward to discuss the details of different port numbers. 

Different Types of Port Numbers and Their Uses

There are around 65535 port numbers in the network. However, there are only a few of them which are practically used. Port numbers are divided into three types: restricted, registerable, and private.

Restricted Ports: Restricted ports are those reserved by prominent companies and only accessible to employees. There are 1023 restricted ports in the range of 0 – 1023. Several services run on these restricted ports, including SQL and Apple QuickTime.

Registerable Ports: These ports can be registered by multiple companies, especially software houses, for their software. The range of these ports is from 1024 to 49151.

Dynamic Ports/Private Ports: These ports are available for anyone. This means anyone can use these ports for their use. The range of dynamic ports is from 49152 to 65535.

Here are a few port numbers with their uses and specific assigned names used in our daily and regular life.

Port 20 / Port 21 – File Transfer Protocol (FTP)

The Port 20 and 21 – File Transfer protocols share files between multiple people. It uses two separate protocols to make things easy to share the files between the client and a server. 

It is widely used all over the world to share back and forth the same file between a client and a server or the cloud.

Port 25 – Simple Mail Transfer Protocol (SMTP)

The port 25 – Simple Mail transfer protocol is used for sending emails. For emails sent to another person, port 25 is in use for sending the email regardless of what email platform you use. 

Port 25 – SMTP helped the world to get closer and gave a reliable source to the world, which helps in sending all kinds of important messages worldwide. An SMTP tester is a tool used to verify the configuration and operation of an SMTP (Simple Mail Transfer Protocol) server.

Port 53 – Domain Name System (DNS)

The Port 53 – Domain Name System is usually used as a compiler but on the internet. The DNS port helps to make all the human-readable text in the IP address to make it a readable machine. 

The port 53 – DNS port made things easy for users to find the right website. The user doesn’t have to write a long IP Address and try multiple IP Addresses to find and open the right website or application. But just writing a domain name can help in opening the right website.

Port 80 – Hypertext Transfer Protocol (HTTP)

The Port 80 – Hyper Text Transfer Protocol helps in the World-Wide Web. When you enter a domain in the browser and hit enter to open the web page. The requests from the browser are sent to the server for display, and as a result, the server sends the request to the browser for display. da

The Port 80 – HTTP has played a big role in browsers and websites. It made it easy for normal people to make their business visible on the internet through the World Wide Web.

Port 443 – Hypertext Transfer Protocol Secure (HTTPS)

The Port 443 – Hyper Text Transfer Protocol Secure works like the Port 80 – Hyper Text Transfer Protocol. Only the difference is that it is more secure and safe when it comes to data. The World Wide Web is also used to ensure the security of data transferred from browser to server or server to browser.

The Port 443 – Hyper Text Transfer Protocol Secure also connects with other ports like port 20, port 21, port 25, and more. It means you can share your personal information like credit card info, personal emails, or other private data through a secure port. 

Port 3389 – Remote Desktop Protocol (RDP)

The Port 3389 – Remote Desktop Protocol helps control your desktop device remotely from another device. This helps you to access and control the desktop even if you are farther from it.

The Port 3389 – Remote Desktop Protocol also helps access a desktop of a completely random IP in your system. This allows the user to use multiple desktops of multiple IPs in the same system.

Conclusion

Port numbers play a crucial role in the functioning of computer networks and the internet. They provide a way for different applications and services to communicate with each other over the network by identifying a unique destination for each communication. Port numbers are unique 16-bit values assigned to specific services and applications, making it possible for network communication to be organized and efficient. Understanding port numbers is important for network administrators, security professionals, and individuals looking to secure their networks, as it helps in identifying potential security vulnerabilities and ensuring compliance with various security standards and regulations.