How to "catch" FORWARD packets in POSTROUTING chain?

[Marcin Sura <slacklist@xxxxx>]

Hello


     I have lan (10.0.0.0/8) and server (10.1.1.1 for lan, dynamic ip
     from my ISP). I use MASQUERADE to allow lan computer connects to
     internet. eth0 connects to lan, ppp0 for internet.

     All traffic lan <--> internet passes through FORWARD chain. How
     can I "catch" this traffic in POSTROUTING chain?

-- 
Pozdrawiam
 Marcin                         mailto:slacklist@xxxxx