Iptables

# apt-get install iptables

iptables uses policy chains to decide the path of a packet to, from, through your system.

Tables

  • FILTER: is the default table with chains INPUT, FORWARD and OUTPUT
  • NAT: used to translate the packet source/destination field with chains PREROUTING, OUTPUT and POSTROUTING
  • MANGLE: packet alteration with chains INPUT, FORWARD, POSTROUTING, PREROUTING and OUTPUT
  • RAW

Chains

  • INPUT: for packet to local machine
  • FORWARD: for packet destined to another net

Jumps

  • http://www.faqs.org/docs/iptables/targets.html