Fail2ban is an intrusion prevention software framework that protects computers from brute-force attacks. It scans log files and bans IP addresses that show malicious signs, such as, too many password failures. Fail2Ban then updates firewall rules to reject the IP addresses for a specified amount of time, although any arbitrary other action (e.g. sending an email) could also be configured.

Public key authentication is an alternative and more secure means of identifying yourself to a login server, instead of typing a password. It is more secure and more flexible, but more involved in its set-up. It can also be used to provide a password-less login experience when using SSH and it can authenticate the system your logging into, thereby assuring your not being spoofed.

This is a step-by-step guide of how to set up your Raspberry Pi as a "headless" computer, that is, access it via network connections without a keyboard or display. This is done by configuring the Raspberry Pi without needing any kind of monitor or keyboard attached. I go a little further by showing how to upgrade the firmware / OS / development tools, bootup without X Windows, setup password-less login, and establish some basic security.

I want to set up a secure connection to my home computer while on the road. The obvious thing to do is open the SSH port on my router, forward it to my SSH port on my computer, and it should be good to go. Yes, but I'm paranoid, so I'm using Two-Factor Authentication.