Re: destinations interface must be eth0?

[Jim Burnett <jburnett@e-masi.com>]

Correct.

You cant DNAT to an IP which isnt bound to eth0 of that DNATed machine.
The gateway of the DNATed machine must point to the firewall also. This
isnt document. This was the case with 9 diferent tested linux distros.



On Tue, 2003-09-16 at 09:22, Ramin Dousti wrote:
> What is not working? That the packets are not being DNATted to 192.168.1.56:80?
> 
> Ramin
> 
> On Mon, Sep 15, 2003 at 09:47:39AM -0500, Jim Burnett wrote:
> 
> > I have found that my destination IP in my rules MUST be bound on eth0
> > what is this? I thought I could use any working IP on my internal
> > network as the --to-destination IP...??
> > 
> > Example:
> > internal machine:
> > eth0:192.168.1.55
> > eth1:192.168.1.56
> > 
> > 
> > #1
> > iptables -v -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j DNA
> > T--to                  192.168.1.55:80
> > This will work because the destination IP is on eth0
> > 
> > #2
> > iptables -v -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j DNA
> > T--to                  192.168.1.56:80
> > This wont work because the destination IP is on eth1
> > 
> > I didnt see this in the documentation and it took my 5 days to figure it
> > out....
> > 
> > Tested on 6 machines, redhat 9, slackware 9, Latest gentoo build from
> > stage 1. Various brand nic cards. Various compiled kernels. 2.4.18 -
> > 2.4.22
> > 
> > -Jim
> > 
> > 
> >