Deploying Linux on IBM eServer pSeries Clusters

3.15. Using iptables for security

The netfilter/iptables project is the Linux 2.4.x / 2.5.x firewalling subsystem.It delivers you the functionality of packet filtering (stateless or stateful), many different kinds of Network Address Translation (NAT) and packet managing. The homepage of Linux iptables is:

http://www.netfilter.org

Iptables is a part of the Linux kernel or more precisely: “netfilter is a set of hooks inside the linux 2.4.x kernel’s network stack which allows kernel modules to register callback functions called every time a network packet traverses one of those hooks”.^[19]

^[19] see http://www.netfilter.org/documentation/

Here we illustrate the use of iptables in a simple example: we have a management server in our environment and ...