Re: PREROUTING

["Eric Poulin" <epoulin@onepost.net>]

You are absolutly right. Actually, the command is correct, and also working
fine in my environement, so I suspect also that some options by be missing in
the kernel.

Eric


> This is not really true ...
>
> According to the iptables man page, DNAT is valid only in the OUTPUT
> and PREROUTING chain of the nat table. SNAT is only valid in the
> POSTROUTING chain of the nat table.
>
> It could be a missing kernel option ...
>
> Frederic Gobin
>
> Am Dienstag, 29.04.03 um 09:49 Uhr schrieb SaVaGE:
>
> > Op dinsdag 29 april 2003 09:23, schreef netfilter_user:
> >> Hello everyone,
> >>
> >> this is my problem:
> >> My LAN is connected to Internet via Linux machine with 2 interface (
> >> ppp0 - for internet and eth1 for local net). I need to connect from
> >> local host, service that is running on port 23073 and 23083 UDP in
> >> internet. For this i wrote afew rules with PREROUTING but when I start
> >> script with rules below i receive:
> >>
> >> Bad argument `PREROUTING'
> >> Try `iptables -h' or 'iptables --help' for more information.
> >> Bad argument `PREROUTING'
> >> Try `iptables -h' or 'iptables --help' for more information.
> >>
> >>
> >> iptables -t nat -A PREROUTING -p udp -d 80.50.60.185 --dport 23073 -j
> >> DNAT
> >> --to-destination 192.168.1.2 iptables -t nat -A PREROUTING -p udp -d
> >> 80.50.60.185 --dport 23083 -j DNAT --to-destination 192.168.1.2
> >>
> >> iptables -A FORWARD -p udp -d 192.168.1.2 --dport 23073 -j ACCEPT
> >> iptables -A FORWARD -p udp -d 192.168.1.2 --dport 23083 -j ACCEPT
> >>
> >> What maybe a reason of this msg?
> >> Im using slackware 8.1 with iptables 1.2.6a
> >
> > This behaviour is correct NATting is done on the POSTROUTING table !!!!
> >
> >
> > Pascal (PC-Secure Dutch security service)
> >
>
>
>
>