Connect to a Linux VPS over SSH - Documentation Infrawire

SSH is the standard way to administer a server: it gives you an encrypted shell on your machine in seconds. This guide shows how to reach your VPS Linux Infrawire from Linux, macOS and Windows, how to verify the server on first contact, and how to save your settings for one-word logins.

📋 Prerequisites

A Linux VPS that is running (Ubuntu 24.04, Debian 12, AlmaLinux 9 or Rocky 9).
The VPS IP address and the root password: from your customer area you can find the IP and the root password of the VPS.
An SSH client: built in on Linux, macOS and Windows 10/11.
Outbound access to the SSH port (22 by default) from your network.

🐧 Connect from Linux or macOS

Open a terminal and run the command below. Replace VPS_IP with the address of your server (IPv4 or IPv6).

Bash
1ssh root@VPS_IP

For an IPv6 address, use the same syntax without brackets:

Bash
1ssh root@2001:db8::10

Type the root password when asked. Nothing is displayed while you type, this is normal. If you prefer a regular account, replace root with USER.

🪟 Connect from Windows 10/11

Windows ships with the OpenSSH client. Open PowerShell or Windows Terminal and use exactly the same command:

PowerShell
1ssh root@VPS_IP

If the command is not found, install the client from an administrator PowerShell:

PowerShell
1Get-WindowsCapability -Online | Where-Object Name -like 'OpenSSH.Client*'
2Add-WindowsCapability -Online -Name OpenSSH.Client~~~~0.0.1.0

🔎 First connection and host key fingerprint

The first time, SSH shows the fingerprint of the server key and asks you to trust it:

TEXT
The authenticity of host 'VPS_IP (VPS_IP)' can't be established.
ED25519 key fingerprint is SHA256:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.
Are you sure you want to continue connecting (yes/no/[fingerprint])?

This protects you against a man-in-the-middle attack. If you have another way into the server, compare the value with the one it reports:

Bash
1ssh-keygen -lf /etc/ssh/ssh_host_ed25519_key.pub

Answer yes. The key is then stored in ~/.ssh/known_hosts and checked at every later login.

🔧 Custom port and ~/.ssh/config

If the SSH daemon listens on another port, pass it with -p (uppercase -P is for scp):

Bash
1ssh -p 2222 root@VPS_IP

To avoid retyping everything, create or edit ~/.ssh/config (on Windows: C:\Users\USER\.ssh\config):

INI
1Host myvps
2    HostName VPS_IP
3    User root
4    Port 2222
5    ServerAliveInterval 30
6    ServerAliveCountMax 3

Restrict the permissions on Linux and macOS, then connect with the alias:

Bash
1chmod 600 ~/.ssh/config
2ssh myvps

The same alias works with scp and rsync, for example scp backup.tar.gz myvps:/root/.

✅ Check that you are connected

Once the prompt appears, confirm that you are on the right machine:

Bash
1hostname
2cat /etc/os-release
3ip -br addr
4who

To leave the session, type exit or press Ctrl+D. For a verbose view of a failing attempt, add -v (up to -vvv):

Bash
1ssh -v root@VPS_IP

🛠️ Troubleshooting

Connection refused. Nothing listens on that port, or a firewall blocks it. Check the IP and the port, then verify the service from the VPS console or another session. The unit is called ssh on Ubuntu/Debian and sshd on AlmaLinux/Rocky:

Bash
1sudo systemctl status ssh
2sudo ss -tlnp | grep sshd
3sudo ufw status

On AlmaLinux/Rocky, check sudo firewall-cmd --list-all and, if you changed the port, allow it there as well.

Permission denied (publickey,password). The password is wrong, the user does not exist, or password login is disabled. Re-read the password from your customer area, check the user name, and look at PermitRootLogin and PasswordAuthentication in /etc/ssh/sshd_config. After any change, run sudo sshd -t and reload the service.

WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED. The key presented differs from the one in known_hosts. This is expected after a reinstall of the VPS, but it can also signal an interception, so be sure of the cause. If it is legitimate, remove the old entry and reconnect:

Bash
1ssh-keygen -R VPS_IP

Connection timed out. The packets never arrive: check the IP, your local firewall or corporate network, and that the VPS is started.

🚀 You can now reach your Linux VPS from any system with a single command. Next step: switch to SSH keys for safer logins.