SSH Cheatsheet

SSH is a secure network protocol used to establish encrypted connections between two computers, allowing for secure data transmission and remote command execution. Here’s a cheatsheet of common SSH commands and practices to help you get started with this essential tool.

1. Establishing SSH Connections

• ssh user@hostname - Establish an SSH connection to a remote host.
• ssh -p port user@hostname - Specify a non-standard port for the SSH connection.
• ssh -J proxy_host user@remote_host - Use a SOCKS proxy for SSH connections.
• ssh -D local_port user@remote_host - Set up a SOCKS proxy on the local machine.
• ssh -L local_portport user@remote_host - Set up a local port forwarding.
• ssh -R remote_portlocal_port user@remote_host - Set up a remote port forwarding.

1. SSH Configuration

• ~/.ssh/config - Manage SSH connection settings in a configuration file.
• Host alias - Define an alias for a hostname in the configuration file.
• DynamicForward - Specify a dynamic port forwarding using a SOCKS proxy.
• LocalForward - Specify a local port forwarding.

1. Key-Based Authentication

• ssh-keygen - Generate an SSH key pair.
• ssh-copy-id user@hostname - Copy your public key to a remote host for key-based authentication.

1. Troubleshooting

• Check the SSH version: ssh -V
• View the SSH logs: tail /var/log/auth.log (Linux)
  Best Practices:

1. Use key-based authentication instead of passwords for added security.
2. Update your SSH software regularly to ensure you have the latest security patches.
3. Limit the number of concurrent SSH sessions to prevent brute-force attacks.
4. Use different port numbers for different services to reduce the risk of port scans.
5. Consider using a VPN or SOCKS proxy for added privacy and security.
   Remember that SSH is a powerful tool, so always be careful with the information you transmit over an SSH connection. It’s important to understand the security implications of each command you run and make sure you follow best practices to keep your data secure.
   If you’re new to SSH, start by familiarizing yourself with the basic commands and concepts. As you become more comfortable, explore the wealth of options and features available to enhance your remote access and data transfer experiences.
   Remember to stay vigilant when using SSH, and don’t hesitate to seek help if you encounter any issues. Happy hacking!
   This article provides a basic overview of SSH, but there’s still much more to explore. If you’re interested in learning more about SSH or related topics, consider checking out online resources, tutorials, or joining a community of like-minded individuals who can share their expertise and experiences.