The Ultimate Common Ports Cheat Sheet in Computer Networking
Tags: beginners, computerscience, linux
Published: 2023-10-07 08:43:46

If you’re a student studying networking or a budding IT courteous,, understanding common ports is essential. Ports serve as data gateways for data to enter and exit a computer, and understanding which services and applications use which ports is critical for network troubleshooting and security. We’ll provide you a complete list of the most often used ports and their associated services in this common ports cheat sheet, making it easier for you to traverse the world of networking.

[What Are Ports in Networking and Types
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## What Are Ports?

Before we go into the list of common ports, let’s define ports and why they’re important in the networking world.

A port number is a 16-bit number with a 0 to 65535 decimal value range. There are three various types of port number spaces: well-known ports (0–1023), registered ports (1024–49151), and dynamic ports (49152-65535).

1. Well-known or Reserved Ports: 0–1023
2. Registered Ports: 1024–49,591
3. Dynamic Ports: 49,592–65,535

These ports can be opened and utilised by operating system services and software programmes to send and receive data via LAN or WAN networks using certain protocols (such TCP, UDP, etc.).

For example, when you visit a website as a web blogger, your computer normally connects to the typical web on port 80 (HTTP) or a secure, virtual web connection to the web server on the port 443 (HTTPS). Goes for it. With whom he communicates. Identifying which port belongs to which service facilitates firewall conversion to network diversion, but results in insufficient defence against the problem.

## What are well-known ports

Well-known ports have port numbers ranging from 0 to 1023. The Internet Corporation for Assigned Names and Numbers (ICANN) assigned these port numbers. These ports, often known as privileged ports, are reserved for common TCP/IP applications.

Each port has been given a specific application. Unencrypted online browsing is done via the Hypertext Transfer Protocol (HTTP) on port 80. POP3 (Post Office Protocol version 3) over port 110 is used to receive emails through a server.

## What are registered ports

Registered ports have port numbers ranging from 1024 to 49,591. Although these port numbers are neither assigned or managed, they can be registered to minimise repetition. The Internet Assigned Numbers Authority (IANA) is the institution that can issue these ports; before, they were assigned by ICANN.

## What are dynamic ports

Dynamic ports, also known as ephemeral ports, are ports that are only active for a short amount of time. They are temporary because they are “opened and closed” as a user is using an application.

Assume I wish to connect to the internet. The first step is, of course, opening a web browser. When you start a web browser and connect to the internet, you will be connected to port 80 (HTTP) or port 443 (HTTPS), depending on the encryption of that web page.

It will select a random open port, such as 49,695, to send that web page to you. When you finish looking at the web page and exit the browser you’re using, the port 49,695 on your end will be closed.

## Common Ports Cheat Sheet

Now, let’s explore the most common ports with which you should acquaint yourself. We’ll categorize them for easier reference.

## Well-Known Ports (0-1023)

These ports commonly associate with widely-used services and applications.

1. Firstly, Port 21 – FTP (File Transfer Protocol) is used for transferring files over a network.
2. Secondly, Port 22 – SSH (Secure Shell) provides secure remote access to systems and secure file transfers.
3. Next, Port 23 – Telnet is a less secure remote access protocol used for managing network devices.
4. Moving on, Port 25 – SMTP (Simple Mail Transfer Protocol) handles outgoing email communication.
5. Additionally, Port 53 – DNS (Domain Name System) resolves domain names to IP addresses.
6. Subsequently, Port 80 – HTTP (Hypertext Transfer Protocol) is used for unencrypted web traffic.
7. Moreover, Port 443 – HTTPS (Hypertext Transfer Protocol Secure) provides secure, encrypted web communication.
8. Furthermore, Port 110 – POP3 (Post Office Protocol version 3) retrieves email from a mail server.
9. Similarly, Port 143 – IMAP (Internet Message Access Protocol) allows access to email on a remote mail server.
10. Lastly, Port 3389 – RDP (Remote Desktop Protocol) enables remote desktop connections.

## Registered Ports (1024-49151)

These ports are frequently linked with applications and services that are less well-known than those in the well-known range but are nevertheless required for certain purposes.

1. Port 3306 – MySQL Serves as a popular database management system.
2. Port 5432 – PostgreSQL Represents another widely-used open-source database management system.
3. Port 8080 – HTTP Alternate (HTTP Proxy) Frequently used as a secondary HTTP port.
4. Port 27017 – MongoDB Addresses high-volume data storage needs through a NoSQL database.
5. Port 5060 – SIP (Session Initiation Protocol) Facilitates voice and video calls across IP networks.
6. Port 6660-6669 – Internet Relay Chat (IRC) Enables real-time text communication.
7. To begin with, Port 3306 – MySQL is a popular database management system.
8. Next up, Port 5432 – PostgreSQL is another widely-used open-source database management system.
9. If you need an alternate HTTP port, Port 8080 – HTTP Alternate (HTTP Proxy) is often used as a secondary HTTP port.
10. For NoSQL database enthusiasts, Port 27017 – MongoDB is a go-to choice for high-volume data storage.
11. In the realm of communication, Port 5060 – SIP (Session Initiation Protocol) facilitates voice and video calls over IP networks.
12. If you’re a fan of real-time text communication, Port 6660-6669 – Internet Relay Chat (IRC) is the way to go.
13. And for secure web communication through an alternate port, don’t forget Port 8443 – HTTPS Alternate (HTTPS Alt).

## Dynamic and Private Ports (49152-65535)

These ports are often used for dynamic, private, or temporary purposes. They are not assigned to specific services but are available for use as needed.

1. Additionally, Port 49152-65535 – Ephemeral Ports (also known as dynamic ports) are used by client applications for temporary purposes, such as establishing connections.

## Additional Ports to Know

While the above ports cover the most common ones, it’s worth mentioning a few more ports that may be important in specific contexts.

Port 161/162 – SNMP (Simple Network Management Protocol) is used in network management to manage and monitor network devices.
For simpler file transfers, Port 69 – TFTP (Trivial File Transfer Protocol) is a viable option.

## Conclusion

Understanding common ports and their associated services is vital for anyone involved in networking or IT systems. This cheat sheet is a helpful resource for navigating the world of networking. Remember that, while these are the most frequent ports, there are many more, and new ones may emerge as technology improves. Maintain your interest and keep learning in order to keep your networking knowledge up to date. Whether you’re a student or an IT professional, this information will help you master the complexities of networking.