IP Masquerade
HOWTO v2.00.110903 covers 2.4, 2.2 and 2.0 kernels,
a step-by-step instruction for setting up IP Masquerade on your Linux box. Version
2.00.110903, last updated on November 9, 2003.
To extract TGZ compressed archive on Linux, run tar
xvzf targetfile.tgz