Quick answer: SSH connection failed: open port 22, verify server IP, check sshd status and on timeout check firewall (UFW).
If you landed here: PuTTY/terminal shows "Connection refused", "Connection timed out" or "Permission denied".
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Frequently asked questions (FAQ)
SSH connection refused – what does it mean?
SSH service not running, port 22 blocked or wrong IP. Check: server online? Port 22 in firewall? sshd active?
SSH connection timed out?
Firewall blocks port 22, wrong IP or server offline. Check UFW/iptables, use panel console (VNC) if needed.
Root login not working?
Use password from panel/billing. For key auth: correct private key? Permissions 600 on ~/.ssh/id_rsa.