Secure Linux server
In the last chapter, we made a few Basic settings that are not essential, but gave us a little color in the terminal, among other things.
The goal of this chapter is to protect the server against attacks.
Now let's move on to the really important things. First, we configure the firewall. Then we change the SSH authentication method from password-based to key-based.
We will still create a "deputy administrator" and block the super administrator root for remote logins.
Finally, we change the SSH port and set up a notification service that sends us an email when someone logs on to the server. These are optional features that you don't have to implement, but are certainly interesting for security fanatics.
The new Linux distribution Ubuntu Server Live makes some tasks obsolete.