Recommend a reading for learning Linux firewalls configuration for beginner?

Question

I am using Linux at home and want to be able to configure firewall. I would like to understand what I am doing not just copy paste some rules from internet :).

Answer 1

If you want to really understand what you are doing, you've got your work cut out for you as iptables is massively complex: frozentux iptables tutorial. This is a highly recommended tutorial (it's free).

If you're willing to break a few bucks: http://www.amazon.com/Linux-Firewalls-3rd-Steve-Suehring/dp/0672327716

Answer 2

Dan Robbins (the creator of Gentoo) wrote a great article on Stateful Firewall Design. It's by far the easiest to understand iptables tutorial.

It says '2.4' however all but the kernel config will apply equally as well to '2.6'. Even though the article is hosted by gentoo (I could have linked to IBM developerworks too) it's distribution independent (except for emerge iptables which should be read as use your package manager to get the iptables command).

Answer 3

I'm a huge fan of the Wiki over at Rackspace Cloud Servers. Their page on IPTables is not as detailed as some of the other stuff out there, but it gets you off the ground without causing too much confusion.

Answer 4

I just stumbled on to this question and I thought I'd add a reference to an IPtables tutorial that I've written. It's more server-oriented, but it might be useful to anyone configuring IPtables for a home computer as well. It does include a lot of information on why each rule is set up the way it is.

http://www.ellipsix.net/geninfo/firewall/index.html

Answer 5

Here's an article I wrote about setting up iptables for a destkop. IPTables for the average desktop user, and another one if you need to connect to a windows (smb) file share network, called IPTables browsing Samba shares.

Answer 6

Your distribution probably has some graphical thingy that allows to check services you want to offer, and outbound traffic you allow. For most uses this should be enough (or at least give a buffer zone until you learn to frob it by hand).