Source NAT

[ISC Jorge Ceron Galvan]

-----Original Message-----
From: /dev/rob0 <rob0 at gmx.co.uk>
To: netfilter at lists.netfilter.org
Date: Wed, 31 Aug 2005 06:37:33 -0500
Subject: Re: Source NAT

> On Wednesday 2005-August-31 06:18, Jimmy wrote:
> > I currently have a situation that I am hoping iptables can resolve.
> > The issue is that I need to NAT the source address based on the
> > destination address. Is that possible with IPTables ?
> 
> Trivial.
> 
> > if dst = 1.1.1.1 src = 10.1.1.1
> 
> iptables -vt nat -A POSTROUTING -d 1.1.1.1 -j SNAT -to 10.1.1.1


why -vt?  

this rule confused me, I'm a begginer;  

what about

iptables -t nat -A POSTROUTING -s 10.1.1.1/24 -j SNAT --to 1.1.1.1

or

iptables -t nat -A POSTROUTING -o eth0 -s 10.1.1.1/24 -j SNAT --to 1.1.1.1


> 
> > Can anyone give me any advice on completing that?
> 
> "man iptables"
> 
> Order matters. If you have a catchall SNAT rule before the specific 
> destination ones, the catchall is the one used.
> 
> NAT != routing. If your SNAT'ed IP addresses need to go out different
> interfaces, this won't work. See the LARTC HOWTO.
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