IPchains uses the concept of an ordered set of "rules" against which network packets are checked. Using ipchains can help to secure your system.
To install ITC's recommended ipchain rules on your system, save the UVAipchains script into your /etc/rc.d/init.d directory. (Shift-click on the link to download to your machine.)
Make sure the script is executable:
chmod +x /etc/rc.d/init.d/UVAipchains
Then run:
/sbin/chkconfig --level 345 UVAipchains on
You
will need to reboot your computer or run the command:
/etc/rc.d/init.d/UVAipchains start
to start ipchains.