"Do you wish you had access to your home file server without
leaving your firewall wide open to attacks? Well today's your lucky
day! While you can implement this on any OS its easiest to do this
on Linux. This article will show you how to lock down your firewall
and implement a port knocker to let you in.
"We are going to achieve this using a Linux firewall and server,
SLED 10.1 to be exact. Yes, you will be playing around with config
files, but I'll give you a template you can work with so you can
just copy/paste and change the things you need to change..."