From mboxrd@z Thu Jan  1 00:00:00 1970
From: Antony Stone <Antony@Soft-Solutions.co.uk>
Subject: Re: icmp echo reply && FORWARD chain
Date: Sun, 2 May 2004 15:46:51 +0100
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On Sunday 02 May 2004 3:24 pm, Jee J.Z. wrote:

> Hi all,
>
> My rules on a gateway linux box (PC2) are set as follows:
>
> Internet(PC1 and so on)-----------(eth0)-PC2-(eth1)-------------Internal
> networks(PC3 and so on...)
>
> iptables -F
> iptables -F -t nat
> iptables -I FORWARD -j QUEUE
> iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to global_ip
> iptables -t nat -A PREROUTING -i eth1 -j DNAT --to 192.168.0.2

That is a weird-looking rule.   Where does IP 192.168.0.2 exist on the above 
diagram?

> ICMP echo request packets from PC1 or PC3 to PC2 can be caught by the
> FORWARD chain queuing to userspace, however, ICMP echo reply (in response
> to ping request from PC2) packets from PC1 or PC3 to PC2 will be ignored by
> the FORWARD chain. Is this a reasonable phenomenon? Could anyone tell me
> the reasons? Thanks a lot in advance!
>
> Cheers,
> Jee

-- 
Ramdisk is not an installation procedure.

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