Cause 1: SSH Service Not Running
Check if SSH service is running: systemctl status sshd (Linux) or Get-Service sshd (Windows)
Cause 2: Firewall Blocking Port 22
Allow SSH through firewall: ufw allow 22/tcp (Ubuntu) or firewall-cmd --add-service=ssh (CentOS)
Cause 3: Wrong IP Address or Port
Verify your server IP address and ensure you're using the correct port (default: 22)
Cause 4: Server Network Issues
Check if your server is reachable: ping your_server_ip