When it comes to securing your web server, one of the key considerations is deciding which port number to open for SSH access. SSH, or Secure Shell, is a cryptographic network protocol that allows secure remote login and command execution on a remote server. By default, SSH operates on port number 22.
Why Change the Default Port?
Changing the default port for SSH can add an extra layer of security to your web server. It can help prevent automated attacks that specifically Target commonly used ports like 22. By using a non-standard port, you make it more difficult for attackers to find and exploit your SSH service.
However, it’s important to note that changing the default port alone is not enough to fully secure your server. It should be used in conjunction with other security measures such as strong passwords, key-based authentication, and firewall rules.
Choosing a New Port
When choosing a new port number for SSH, there are a few factors to consider:
- Avoid well-known ports: Well-known ports are those in the range of 0-1023 and are assigned by the Internet Assigned Numbers Authority (IANA) for specific services. It’s best to avoid using these ports for SSH or any other non-standard service.
- Select a high-numbered port: High-numbered ports (above 1024) are generally used for custom or less common services.
Using a high-numbered port for SSH can reduce the likelihood of conflicts with other services running on your server.
- Avoid commonly used ports: While high-numbered ports are less likely to be Targeted by automated attacks, some common ports like 2222 or 8022 have become popular alternatives to port 22. It’s best to choose a port that is less likely to be used by other services.
Configuring SSH to Use the New Port
Once you’ve chosen a new port number, you need to configure your SSH server to listen on that port:
Open your SSH server configuration file, usually located at
/etc/ssh/sshd_config, using a text editor. Look for the line that specifies the port number and modify it accordingly. For example:
#Port 22 Port 2222
# character at the beginning of the line, if present, and change the port number to your desired value. Save the file and restart the SSH service for the changes to take effect.
In conclusion, changing the default SSH port can enhance the security of your web server by making it less susceptible to automated attacks. By following best practices and selecting a non-standard, high-numbered port, you can add an extra layer of protection without significant inconvenience. Remember to also implement other security measures in conjunction with changing the SSH port for optimal server security.