Connect to your Linux server with SSH

SSH (Secure Shell) is how you manage a Linux server: it opens an encrypted terminal session on the server from your own computer. This guide takes you through your first login to a new HyperDC Linux VPS, VDS or dedicated server, from finding the login details to checking that you really reached your server.

Before you start

You need:

• Your server's login details. We email them as soon as the server is ready: the IP address, the user name (usually root) and the password. The IP address and user name are also on the service page in the client area: Services › My Services, open the server, then look under Server Information (Primary IP, Username).
• A terminal with an SSH client. Windows 10 and 11, macOS and Linux all include one. On Windows you can also use PuTTY.
• Network access to port 22. Some office and public networks block outgoing SSH. If you cannot connect from one network, try another, for example a mobile hotspot.

In the examples below, replace 203.0.113.10 with your server's IP address.

Step 1: Open a terminal and connect

Choose the tab for your computer.

ssh root@203.0.113.10

Add-WindowsCapability -Online -Name OpenSSH.Client~~~~0.0.1.0

ssh root@203.0.113.10

ssh root@203.0.113.10

If your server listens on a different SSH port, add it with -p, for example ssh -p 2222 [email protected].

Step 2: Check the host key and log in

On the first connection, your SSH client cannot know the server yet, so it shows the server's host key fingerprint and asks whether to trust it:

The authenticity of host '203.0.113.10 (203.0.113.10)' can't be established.
ED25519 key fingerprint is SHA256:2mI0p7Wb0tV5c9Qk3oXyQm0ZQ1u8s3Jd6l0v4WqT1nE.
This key is not known by any other names.
Are you sure you want to continue connecting (yes/no/[fingerprint])?

The fingerprint proves which server you are talking to. If your service page offers a web console, you can open it, log in there and print the real fingerprint for comparison:

ssh-keygen -lf /etc/ssh/ssh_host_ed25519_key.pub

When the fingerprints match, type yes and press Enter. Your computer stores the key in its list of known hosts and will warn you if it ever changes. Then enter the password from your welcome email. Nothing appears while you type; that is normal.

Verify: a successful login ends at a prompt such as root@srv12345678:~#. Run these commands to confirm where you are:

whoami
hostname
cat /etc/os-release
ip -brief address

You should see root, your server's host name, the operating system you ordered and your server's IP address on the network interface.

Step 3: Change the root password

The password in the welcome email has travelled by email, so replace it now with a long password of your own (a password manager can generate one):

passwd

Enter the new password twice. Verify: the command ends with password updated successfully.

Step 4: Have a quick look around

These commands show how much disk space and memory the server has and how long it has been running:

df -h /
free -h
uptime

When you are done, close the session with exit. If a session ever freezes, press Enter, then type ~. to close it from your side.

Troubleshooting

Connection timed out. Your packets do not reach the server. Check the IP address, then test the port: Test-NetConnection 203.0.113.10 -Port 22 in PowerShell, or nc -vz 203.0.113.10 22 on macOS and Linux. If the port is closed from every network you try, the server may be stopped, still being set up, or a firewall rule may block SSH. See SSH connection problems and, if you changed the firewall, locked out after a firewall change.

Connection refused. The server answered, but nothing listens on that port. The SSH service may be stopped or listening on another port. Log in through the web console if your service page offers one and run systemctl status ssh.

Permission denied, please try again. The user name or password is wrong. Passwords are case-sensitive; paste the password again without extra spaces. If you have changed it and forgotten it, open a support ticket from the client area.

Permission denied (publickey). The server accepts SSH keys only, and your key was not accepted. See SSH keys to add the right key.

WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! The server's host key is different from the one your computer stored. This is expected after you reinstall the operating system; otherwise treat it as a warning sign and check with us. After a reinstall, remove the old key and connect again:

ssh-keygen -R 203.0.113.10

For more detail on any failure, connect with ssh -v [email protected] and read the lines just before the error.

Next steps

• Replace password logins with keys: SSH keys.
• Work through the first-hour checklist: secure a new Linux server.
• Point your domain at the server: point a domain to your server.
• Running Windows instead? See first steps on a Windows server.