So, you just got your first server. Maybe it's a VPS you're renting, or maybe it's running off your home Internet connection. The main point is that it's connected directly to a public IP address, so you can access it from anywhere. That means you can share things with other people or access your data on the go, but it also means that you've entered the domain of hackers, distributed denial-of-service (DDoS) attackers, and other nefarious folk who roam the Internet looking for weak links in security. You need to batten down the virtual hatches and bar the digital door: You're now responsible for securing your own domain. Let's look at the first things you need to do to ensure you stay safe (see "Picking a Distro" for more information).

If you're renting your server, then the chances are that you're first interaction with it is via Secure Shell (SSH). This protocol allows you to create an encrypted shell session to your server and generally use it as though it were a local server. The power that comes with SSH is the reason it's the most common target for attackers. If you have a server on a public IP address, people will attempt to log in via SSH, and usually this starts happening almost instantly.

When it comes to server security, SSH is the place to start. The first rule is never, not even temporarily, use a default password to log in with. We're looking particularly at people using Raspberry Pis, but it goes with anything. If you have to login via password, it should be a randomly generated long string of characters, but we won't delve too far into password rules, because we'll move swiftly on to the second rule of SSH: Disable password login as soon as possible.

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