Where does linux kernel ipsec hook in

["Johannes Kleimola" <johannes@xxxxxxxxxxx>]

Hi!

This may have been asked before, but could somebody tell me where does

  1) linux 2.6 kernel ipsec (encrypt and decrypt) and
  2) linux packet sniffers (tcpdump, ethereal)

hook in all the diagrams of page:

http://www.faqs.org/docs/iptables/traversingoftables.html

Thank you very much for help!

  >> Johannes <<