How can I easily manage iptables ?

With a GUI based iptables configuration program called FireStarter.

Note: If you installed your server without a GUI then FireStarter is not for you.

Firestarter RPM Centos 6

As the writing of this article I could not find an RPM package in the repositories for firestarter-1.0.3-1

Lets build one from the srpm ( http://wiki.centos.org/HowTos/SetupRpmBuildEnvironment is a great source for reference on RPM building )

Need install rpm-build

# yum install rpm-build

Also install rpm-config that contains build macros and extra scripts

# yum install redhat-rpm-config

Install build packages

# yum install make gcc gcc-c++

Download firestarter src.rpm

http://www.fs-security.com/download.php

Install the src.rpm ( http://wiki.centos.org/HowTos/RebuildSRPM reference for building RPM packages from src.rpm )

# rpm -i firestarter-1.0.3-1.src.rpm

Firestarter no longer shows “active connections” fix

Bugzilla report – Bug 245321

Lets update the source files to fix a bug in filestarter. The problem is that firestarter is looking for the file /proc/net/ip_conntrack but recent kernels (>=2.6.21) have renamed the file to /proc/net/nf_conntrack

# cd ~/rpmbuild/SOURCES

Untar the source file

# tar -xzvf firestarter-1.0.3.tar.gz

Modify the statusview.c file

# cd firestarter-1.0.3/src

# vi statusview.c

Change the line

#define CONNTRACK_FILE "/proc/net/ip_conntrack"

TO

#define CONNTRACK_FILE "/proc/net/nf_conntrack"
Re-Tar the source
# tar -czvf firestarter-1.0.3.tar.gz firestarter-1.0.3
Create the firestarter Centos 6 RPM
Go to the unpacked SRPM files and find the .spec file
# cd ~/rpmbuild/SPECS
Lets make the firestarter rpm
# rpmbuild -ba firestarter.spec
error: Failed build dependencies: 
glib2-devel >= 0:2.4 is needed by firestarter-0:1.0.3-1.x86_64
gtk2-devel >= 0:2.4 is needed by firestarter-0:1.0.3-1.x86_64
gnome-vfs2-devel >= 0:2.6.0 is needed by firestarter-0:1.0.3-1.x86_64
libglade2-devel >= 0:2.3.6 is needed by firestarter-0:1.0.3-1.x86_64
libgnomeui-devel is needed by firestarter-0:1.0.3-1.x86_64
perl-XML-Parser is needed by firestarter-0:1.0.3-1.x86_64
Looks like we need to install some pakcages in order to create our firestarter rpm.
#yum install  glib2-devel gtk2-devel gnome-vfs2-devel libglade2-devel libgnomeui-devel perl-XML-Parser
Lets try it again
# rpmbuild -ba firestarter.spec
Lets go get the rpm we just created
# cd ~/rpmbuild/RPMS/x86_64  ( this is because I am on a 64bit system for 32bit systems the last folder will be different )
Lets install our firestarter-1.0.3-1 rpm
# rpm -Uvh firestarter-1.0.3-1.x86_64.rpm
Preparing...                ########################################### [100%]
1:firestarter            ########################################### [100%]
You will find the Firestarter icon in your desktop’s programs menu OR run the program by executing “firestarter” from the command line
 
Configure FireStarter



Firestarter has good documentation on how to use Firestarter, I recommend taking a few minutes and going through each one of these pages.
The main components of the Firestarter interface are:

The status page

This page in the main interface gives you a quick overview of the state of the firewall as well as allowing you start and shut it down.
The events page

The second page in the main interface, the events page contains the intrusion attempt history of the firewall.
The policy page

The final page in the main interface, the policy page is where you review your access policy. The policy alone determines what is allowed through the firewall.
The preferences

The program preferences control many aspects of the interface, as well as giving you the option to enable some additional filtering functions of the firewall.