Subj : Re: IPTables forwarding rule
To   : alt.linux,alt.os.linux,comp.os.linux,aus.computers.linux
From : Black Adder
Date : Wed Jul 21 2004 10:01 pm

I had a client similar to that too.  I threw in an IPCOP box for them, and
took out the firewall

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"It's all coming back to me now", said the blind man as he peed into the
wind
"Harry Phillips" <harry@hkjsfh.com> wrote in message
news:i7p1t1-n1u.ln1@free.teranews.com...
> I have a client with a firewall device that has a limited interface to
> iptables (I cannot ssh into it either). All you can do is forward a port
> to another IP address, you can't restrict it to a certain source IP.
>
> I have set it up to forward port 22 to my Linux box, that then has
> IPTables to accept anything local and drop everything else except my
> ADSL modem IP.
>
> Now I want to do a similar thing except forward the packets to another
> internal host. I have no idea where to start and what rules to use. The
> setup is:
>
>                   _____________________
>                  |  (firewall device)  |     |---> |192.168.1.50|
> internet <----> |ext_ip  192.168.1.254| <---|---> |192.168.1.1 |
>                  |_____________________|     |---> |192.168.1.x |
>
>
> I want the Linux box (192.168.1.1) to forward port x to 192.168.1.50,
> but only if the source is my ADSL modem IP.
>
> Do I use the NAT and PREROUTING, POSTROUTING, FORWARD? I have examples
> from the Internet if the Linux box and the host it is forwarding to are
> on different networks but not when they are on the same network.
>
> -- 
> Regards,
> Harry Phillips

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