Change SSH Port To A Different Value Other Than 22

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Introduction

Secure Shell (SSH) is a secure protocol used for remote access to servers and other network devices. The default SSH port is 22, but changing it to a different value can improve security by making it more difficult for hackers to access your system. In this article, we will guide you through the process of changing the SSH port to a different value other than 22.

Why Change the SSH Port?

Changing the SSH port is an essential step in securing your system. Here are some reasons why you should consider changing the default SSH port:

  • Reduced risk of brute-force attacks: By changing the default SSH port, you reduce the risk of brute-force attacks, where hackers try to guess the port number.
  • Improved security: Changing the SSH port makes it more difficult for hackers to access your system, even if they have obtained your IP address.
  • Compliance with security standards: Changing the SSH port is a requirement for some security standards, such as PCI-DSS.

Preparation

Before changing the SSH port, you need to prepare your system. Here are the steps to follow:

Step 1: Backup Your System

Before making any changes to your system, it is essential to backup your data. This will ensure that you can restore your system to its previous state if something goes wrong.

Step 2: Check the SSH Port

Check the current SSH port by running the following command:

ss -tlnp | grep ssh

This command will display the current SSH port number.

Step 3: Choose a New SSH Port

Choose a new SSH port number that is not commonly used. You can use a port number between 1024 and 65535. Avoid using port numbers that are commonly used by other services, such as port 80 (HTTP) or port 443 (HTTPS).

Changing the SSH Port

Now that you have prepared your system, you can change the SSH port. Here are the steps to follow:

Step 1: Edit the SSH Configuration File

Edit the SSH configuration file using a text editor, such as nano or vim. The file is usually located at /etc/ssh/sshd_config.

Step 2: Change the SSH Port

Change the SSH port number by adding the following line to the configuration file:

Port <new_port_number>

Replace <new_port_number> with the new port number you chose.

Step 3: Save the Configuration File

Save the configuration file and exit the text editor.

Step 4: Restart the SSH Service

Restart the SSH service to apply the changes. The command to restart the SSH service varies depending on your system. Here are some common commands:

  • Ubuntu/Debian: sudo service ssh restart
  • Red Hat/CentOS: sudo service sshd restart
  • Fedora: sudo systemctl restart sshd

Testing the New SSH Port

After changing the SSH port, you need to test it to ensure that it is working correctly. Here are the steps to follow:

Step 1: Connect to the Server Using the New SSH Port

Connect to the server using the new port number. You can use a tool like ssh or a graphical SSH client like PuTTY.

Step 2: Verify the Connection

Verify that the connection is working correctly by checking the SSH version and the port number.

Troubleshooting

If you encounter any issues while changing the SSH port, here are some common troubleshooting steps to follow:

Step 1: Check the SSH Configuration File

Check the SSH configuration file to ensure that the new port number is correct.

Step 2: Restart the SSH Service

Restart the SSH service to apply the changes.

Step 3: Check the System Logs

Check the system logs to see if there are any errors related to the SSH service.

Conclusion

Changing the SSH port to a different value other than 22 is an essential step in securing your system. By following the steps outlined in this article, you can change the SSH port and improve the security of your system. Remember to backup your system before making any changes and to test the new SSH port to ensure that it is working correctly.

Best Practices

Here are some best practices to keep in mind when changing the SSH port:

  • Use a unique port number: Use a unique port number that is not commonly used by other services.
  • Document the new port number: Document the new port number and keep it secure to prevent unauthorized access.
  • Test the new port number: Test the new port number to ensure that it is working correctly.

Common SSH Port Numbers

Here are some common SSH port numbers that you should avoid using:

  • 22: The default SSH port number.
  • 80: The HTTP port number.
  • 443: The HTTPS port number.
  • 21: The FTP port number.

Conclusion

Introduction

Changing the SSH port to a different value other than 22 is an essential step in securing your system. However, many users are unsure about how to change the SSH port or have questions about the process. In this article, we will answer some of the most frequently asked questions about changing the SSH port.

Q: Why do I need to change the SSH port?

A: Changing the SSH port is an essential step in securing your system. By changing the default SSH port, you reduce the risk of brute-force attacks and make it more difficult for hackers to access your system.

Q: How do I choose a new SSH port number?

A: You can choose a new SSH port number between 1024 and 65535. Avoid using port numbers that are commonly used by other services, such as port 80 (HTTP) or port 443 (HTTPS).

Q: How do I change the SSH port on my Linux system?

A: To change the SSH port on your Linux system, you need to edit the SSH configuration file. The file is usually located at /etc/ssh/sshd_config. Add the following line to the configuration file:

Port <new_port_number>

Replace <new_port_number> with the new port number you chose. Save the configuration file and restart the SSH service.

Q: How do I change the SSH port on my Windows system?

A: To change the SSH port on your Windows system, you need to edit the SSH configuration file. The file is usually located at C:\Program Files\OpenSSH\sshd_config. Add the following line to the configuration file:

Port <new_port_number>

Replace <new_port_number> with the new port number you chose. Save the configuration file and restart the SSH service.

Q: How do I test the new SSH port?

A: To test the new SSH port, you need to connect to the server using the new port number. You can use a tool like ssh or a graphical SSH client like PuTTY.

Q: What if I encounter an error while changing the SSH port?

A: If you encounter an error while changing the SSH port, you can try the following:

  • Check the SSH configuration file to ensure that the new port number is correct.
  • Restart the SSH service to apply the changes.
  • Check the system logs to see if there are any errors related to the SSH service.

Q: Can I change the SSH port back to the default port?

A: Yes, you can change the SSH port back to the default port by editing the SSH configuration file and removing the Port line. Save the configuration file and restart the SSH service.

Q: Is it safe to change the SSH port?

A: Yes, it is safe to change the SSH port. However, you should make sure to backup your system before making any changes and to test the new SSH port to ensure that it is working correctly.

Q: Can I use a dynamic SSH port?

A: Yes, you can use a dynamic SSH port. A SSH port is a port number that is randomly assigned each time you connect to the server. To use a dynamic SSH port, you need to add the following line to the SSH configuration file:

Port 0

This will allow the SSH service to use a dynamic port number.

Conclusion

Changing the SSH port to a different value other than 22 is an essential step in securing your system. By following the steps outlined in this article, you can change the SSH port and improve the security of your system. Remember to backup your system before making any changes and to test the new SSH port to ensure that it is working correctly.