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From: "Hard__warE" <hard__ware@hotmail.com>
To: netfilter@lists.samba.org
Subject: SNAT of ICMP fragmentation-nee
Date: Mon, 10 Jun 2002 22:56:32 +1000	[thread overview]
Message-ID: <000501c2107e$3ed0f300$7b0010ac@dynamicaccess.lan> (raw)

> iptables -I POSTROUTING  -t nat -p icmp --icmp-type \
> fragmentation-needed -j LOG --log-prefix "icmp SNAT POST "
>
> iptables -I PREROUTING -t mangle  -p icmp --icmp-type \
> fragmentation-needed -j LOG --log-prefix "icmp SNAT PRE "
>

do you need to log all interfaces / chains

or a particular adapter ????

ok have you tried using this instead

$IPTABLES -t nat -A POSTROUTING -p icmp --icmp-type \
fragmentation-needed -j LOG --log-prefix "icmp SNAT POST "

$IPTABLES -t nat -A PREROUTING -p icmp --icmp-type \
fragmentation-needed -j LOG --log-prefix "icmp SNAT PRE "

....

oh and this one is for

Antony Stone ... :D ... Gday ..

>Hmmm.   Okay - this is beyond my understanding of netfilter - can anyone
else
>suggest why icmp packets going through the machine would get logged and
>processed by PREROUTING and FORWARD but not by POSTROUTING ?

i have tested this with ICMP and it iz very true ...

It seems as if the IPtables Box handles the actuall ICMP traffic locally

So a box on the local lan can ping someone on the net and in your

POSTROUTING Stage the packets arnt logged ...

packets may flow through the actuall Theroy of Prerouting ---> Forward -->
Postrouting

and actually not go through the Postrouting stage ...

I found by using IP alias's and a few modifications to your IPTables script
you can acheive alot of

things that are thought to be not possible .... :D .. hehhe








             reply	other threads:[~2002-06-10 12:56 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-06-10 12:56 Hard__warE [this message]
     [not found] <Pine.LNX.4.44.0206101340570.30649-100000@albert.ha-vel.cz>
2002-06-10 12:18 ` SNAT of ICMP fragmentation-nee Antony Stone
2002-06-10 14:52   ` Ramin Alidousti
2002-06-10 15:01     ` Antony Stone
2002-06-10 16:06   ` Jack Bowling
2002-06-10 18:03     ` Ramin Alidousti

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