How To Troubleshoot SSH Connection Refused

Have you ever tried to SSH into a server and been met with the dreaded “connection refused” error? It’s frustrating, but don’t worry, this guide is here to help you troubleshoot and get back on track quickly.

What is SSH and Why Do We Use It?

SSH (Secure Shell) is a protocol for securely accessing and controlling computers remotely. Think of it as a secure tunnel that lets you manage files, run commands, and install software on a distant machine as if you were sitting right in front of it.

Why am I Getting “Connection Refused”?

There are several common culprits behind this error:

• SSH Server Not Running: The SSH server on the remote machine might not be active.
• Firewall Blocking SSH: A firewall could be preventing incoming SSH connections.
• Incorrect Port Configuration: SSH usually runs on port 22, but it could be configured differently.
• Incorrect Credentials: Double-check your username and password!
• Network Connectivity Issues: Problems with your network could prevent the connection.
• SSH Configuration Errors: Misconfigurations on either the client or server can cause this issue.

Let’s Get It Fixed!

1. Is Your SSH Server Running?

   • How to Check: Run sudo service ssh status in your server’s terminal.
   • How to Fix: If it’s not running, start it with sudo service ssh start.

2. Check Your Firewall:

   • How to Fix: Open port 22 (or your configured SSH port) in your firewall settings. The exact command depends on your firewall, but here’s an example for Ubuntu’s UFW: sudo ufw allow ssh.

3. Verify Your Port Configuration:

   • How to Check: Look in the /etc/ssh/sshd_config file on the server for the Port setting.
   • How to Fix: If it’s not 22, use the correct port when connecting (ssh -p [port number] user@host).

4. Double-Check Your Credentials:

   • Usernames and passwords are case-sensitive, so be sure to type them correctly.
   • If you’ve forgotten your password, reset it on the server.

5. Check Network Connectivity:

   • How to Check: Try pinging the server (ping [server IP address]) to see if it’s reachable. If not, troubleshoot your network connection.

Bonus Tips:

• Use the Verbose Flag: The -v flag (ssh -v user@host) will give you more detailed error messages, making it easier to diagnose the problem.
• Check the Logs: SSH logs (usually in /var/log/auth.log) can provide clues about what’s going wrong.
• Consult Server Documentation: If you’re still stuck, check the server’s documentation or ask the server administrator for help.