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Troubleshooting SSH Connections

Early Access: Ultra.sh is currently in early access. Features, plans, and documentation may change as we continue to improve the service. If anything here does not match what you see, open a support ticket and let us know.

Troubleshooting SSH Connections

This guide covers common SSH connection problems on your VPS. You can also connect with an SSH client such as Termius. This guide uses the ssh command in a terminal.

Run the SSH commands below on your own computer, not in the VPS console, unless a step says otherwise. Replace SERVER_IP with the IP address of your VPS.

Check Your Details

Your client area email address and password are not your VPS login credentials.

  • Confirm that you are connecting to the IP address of your VPS. You can find it in either of these places:
    • In the client area, open your service and copy the Primary IP from the Overview tab.
    • In the panel, open your server and copy the ADDRESS from the Network section of the Overview tab. Do not include the /24 suffix.
  • Use root as the username. If you created another user on your VPS and configured SSH access for it, use that username instead.
  • Use TCP port 22 unless you changed the SSH server configuration. If you changed it, replace 22 in the commands with your configured port and update any saved SSH client profile to match.
  • Use lowercase -p to specify the port with OpenSSH.

Connect with:

ssh -p 22 root@SERVER_IP

If you created your key with Generate an SSH Key Pair, the key has a custom name (id_ed25519_ultrash) that SSH does not offer by default. Pass it with the -i option. On macOS and Linux, use:

ssh -i ~/.ssh/id_ed25519_ultrash -p 22 root@SERVER_IP

In Windows PowerShell, use:

ssh -i $env:USERPROFILE\.ssh\id_ed25519_ultrash -p 22 root@SERVER_IP

If SSH displays Permission denied, the server responded but did not accept your login. Check the username and authentication method before trying again.

  • For password authentication, use your VPS root password, or the password for the user you created. If you lost the root password, see Reset the Root Password.
  • Password logins over SSH work only while the Password login over SSH switch is on. To check it, open your server in the panel and go to Settings > Security. The VPS must be running to change the switch. A password that works in the console does not necessarily work over SSH.
  • Update saved credentials after changing the VPS password.
  • Password characters do not appear while you type in a terminal. This is normal.

Other connection errors can help narrow down the problem:

  • Connection refused usually means no service is accepting connections on that address and port, or a firewall is actively rejecting the connection.
  • Connection timed out means the connection received no response. An incorrect IP address, firewall rule, network restriction, or unavailable VPS can cause this.
  • If the connection times out, check that your VPS is online. In the panel, the STATE on the Overview tab shows Running when the VPS is online. Then try a trusted VPN or another internet connection, such as a mobile hotspot. If SSH works there, the problem may be specific to your original network or connection.

Check Your SSH Key

SSH key authentication requires a matching pair. The public key belongs on the VPS, and the private key stays on your computer.

  • Use the private key that matches the public key you supplied when configuring access to this VPS.
  • The matching public key must be authorized for the account you are trying to access. Keys saved in the panel under Settings > Security > SSH Keys can log in as root, and the VPS must be running when you save them. To use a key with another user, authorize it for that user inside the VPS. See Manage SSH Keys.
  • Do not use the public key file, usually ending in .pub, as your private key.
  • Specify the private key explicitly to avoid using an unrelated saved key.
ssh -o IdentitiesOnly=yes -i "/path/to/private_key" -p 22 root@SERVER_IP

Replace /path/to/private_key with the location of your private key. Keep the quotation marks if the path contains spaces.

If SSH displays Permission denied (publickey), it did not accept the key for that account. Recheck the username and matching key pair.

If SSH displays Too many authentication failures, your client may be offering several keys. The command above limits it to the specified identity.

On macOS or Linux, SSH may reject a private key if other users can read it. If the error reports an unprotected private key, restrict access to the file owner using:

chmod 600 "/path/to/private_key"

Warning: Never share your private key or paste it into the panel or a support ticket.

Resolve a Host Key Warning

If SSH displays REMOTE HOST IDENTIFICATION HAS CHANGED!, the server's host key differs from the one saved on your computer. Reinstalling your VPS can generate a new host key, but an unexpected change could indicate that you are connecting to the wrong server or that your connection is being intercepted.

  • Confirm that the IP address and port belong to your VPS.
  • Get the trusted fingerprint from the VPS itself. Open the browser console (see Access the Console), log in, and run:
ssh-keygen -lf /etc/ssh/ssh_host_ed25519_key.pub
  • Compare the SHA256: value in the output with the fingerprint your SSH client shows. If they do not match, do not continue and contact support.
  • Only after verifying that the change is legitimate, remove the old saved host key on your own computer. For port 22, use:
ssh-keygen -R SERVER_IP
  • If you use a different SSH port, replace PORT with that port and use:
ssh-keygen -R "[SERVER_IP]:PORT"
  • Connect again using your usual SSH command. Compare the displayed fingerprint with the one from the console, and accept the new host key only if they match.

Warning: Do not disable host key checking or accept an unverified replacement key.

Use the Browser Console

If SSH still fails, open your VPS browser console from the panel. The console provides another way to access the VPS when SSH is unreachable. For steps, see Access the Console.

Contact support if the problem continues. Include the VPS name or IP address, the action you tried, and any error message shown.

If you require further assistance, you can open a support ticket here.