Using the firewall in Ubuntu can be as easy or as hard as you want to make it. BSD variants all basically use the ipfw command whereas most of the rest of the *nix world will use netfilter. Netfilter has a number of front ends; the one that comes pre-installed in Ubuntu is ufw, short for ‘uncomplicated firewall’. Ufw is good for basic port management: allow and deny type of stuff. It’s not going to have the divert or throttling options. So let’s look at some basic incantations of ufw (you need to have elevated privileges to do all of this btw). Initial Configuration First you need to enable ufw,…