ports

Kernel Configuration:

A firewall in Linux is accomplished through a portion of the kernel called netfilter.
The interface to netfilter is Iptables. To use it, the appropriate kernel
configuration parameters are found in:

[*] Networking support  --->                                    [CONFIG_NET]
      Networking Options  --->
        [*] Network packet filtering framework (Netfilter) ---> [CONFIG_NETFILTER]


Installation of Iptables:

The installation below does not include building some specialized extension libraries
which require the raw headers in the Linux source code. If you wish to build the
additional extensions (if you aren't sure, then you probably don't), you can look at
the INSTALL file to see an example of how to change the KERNEL_DIR= parameter to
point at the Linux source code. Note that if you upgrade the kernel version, you may
also need to recompile Iptables and that the BLFS team has not tested using the raw
kernel headers.

For some non-x86 architectures, the raw kernel headers may be required. In that case,
modify the KERNEL_DIR= parameter to point at the Linux source code.