RE: Linux NAT questions

["Michel Wilson" <michel@procyon14.yi.org>]

> what I am trying to do is this. I have a genuine network, say 1.1.1.x, and
> my Linux host is on it, as 1.1.1.252 (eth0). I also have a second
> network at
> the back of the Linux box, 192.168.200.x, and a web server on
> that network,
> 192.168.200.2. The Linux address is 192.168.200.1 on eth1.
>
> What I want to do is make the web server appear on the 1.1.1.x network as
> 1.1.1.160. I have done this before with Firewall-1 on NT, by
> putting an arp
> entry for 1.1.1.160 to point to the Linux machine eth0. The packets get
> redirected into the Linux machine, then translated, and then routed out of
> eth1.
>
> The benefit is that there is no routing change to the 1.1.1.x network, and
> the Linux box isn't even seen as a router.
>
> I would appreciate any help with this. Any command to do this?
>
> Chee Tong
This isn't really a kernel question. I think you'd better ask it on some
linux network list/newsgroup. But here's an answer anyway....

You could add 1.1.1.160 to eth0:
   ip addr add 1.1.1.160 dev eth0
and then use NAT to redirect these to the webserver:
   iptables -t nat -A PREROUTING -p tcp --dst 1.1.1.160 -i eth1 -j
DNAT --to-destination 192.168.200.2

This should work, AFAIK, but i didn't try it myself. You could also try to
use the arp command (see 'man arp'), but i don't know exactly how that
works.

Good luck!

Michel Wilson.