From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andreas Jellinghaus <aj@dungeon.inka.de>
Subject: iptables and 2.5.* ipsec
Date: 14 May 2003 11:53:59 +0200
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To: netfilter@lists.netfilter.org

Hi,

How does 2.5.* ipsec and netfilter interact?

I guess this way, but I'm not sure:
(encrypted) network card -> routing -> INPUT -> decrypt
(decrypted) ipsec -> routing -> INPUT/FORWARD 

A normal packet is processed this way:
ipsec -> routing -> INPUT/FORWARD 

The first is easy to see: proto 50 or 51 (or udp port 500 for ike).
But how can I see whether an unencrypted packet came in unencrypted
or came in encrypted via ipsec?

with freeswan I could match -i ipsec0, but with kernel 2.5.* there
is no ipsec0 device. What shall I use instead? fwmark?

Thanks for your help.

Regards, Andreas