I won't ruin the RSS with a huge image, but here's a graphical flow of iptables/netfilter. Netfilter is an awesomely complex beast, as the image shows.
An absolute fail distro. Really, I recommend Windows XP anytime over Ubuntu. (But of course, SUSE/Fedora in the pole position still.)
I appreciate Jan's contribution and dedication to kernel.org and elsewhere; I will leave it to others to debunk or affirm his individual complaints. But framing the complaints of a kernel hacker as applicable to Windows users is disingenuous.