Very basic question.

Very basic question.

[tom]

Hi,

            I am very new to trying to use iptables and was wondering if
someone could help me out with what I should do to solve my current problem.

I have a PC with 3 ethernet cards, one is connected to the internet (eth2).
I want to use network translation to forward all requests to a pair of
static IP addresses I have to particular locales on an internal network
(which is accessed through eth1).

Ie forward all incoming traffic on eth2 going to address 213.249.230.206 to
192.168.10.2 on eth1.

 

I have tried the following, but it just seems to redirect all traffic to the
local firewall:

 

iptables -t nat -A POSTROUTING -o eth1 -s 192.168.10.2 -j SNAT --to
213.249.230.206

iptables -t nat -A PREROUTING -i eth2 -s 213.249.230.206 -j DNAT --to
192.168.10.2

 

What am I doing wrong?

 

Tom 

Very basic question

[coding]

Hi,

            I am very new to trying to use iptables and was wondering if
someone could help me out with what I should do to solve my current problem.

I have a PC with 3 ethernet cards, one is connected to the internet (eth2).
I want to use network translation to forward all requests to a pair of
static IP addresses I have to particular locales on an internal network
(which is accessed through eth1).

Ie forward all incoming traffic on eth2 going to address 213.249.230.206 to
192.168.10.2 on eth1.

 

I have tried the following, but it just seems to redirect all traffic to the
local firewall:

 

iptables -t nat -A POSTROUTING -o eth1 -s 192.168.10.2 -j SNAT --to
213.249.230.206

iptables -t nat -A PREROUTING -i eth2 -s 213.249.230.206 -j DNAT --to
192.168.10.2

 

What am I doing wrong?

 

Tom 

 

Re: Very basic question

[Eric Leblond]

On Fri, 2004-09-24 at 12:28, coding@digital-data.co.uk wrote:
> Hi,
> 
>             I am very new to trying to use iptables and was wondering if
> someone could help me out with what I should do to solve my current problem.

> Ie forward all incoming traffic on eth2 going to address 213.249.230.206 to
> 192.168.10.2 on eth1.

only one is enough 

> iptables -t nat -A PREROUTING -i eth2 -s 213.249.230.206 -j DNAT --to
> 192.168.10.2

traffic to 213.249.230.206 thus -d not -s :
iptables -t nat -A PREROUTING -i eth2 -d 213.249.230.206 -j DNAT --to
192.168.10.2
-- 
Eric Leblond <eric@inl.fr>
INL

Re: Very basic question.

[Alejandro Flores]

	Hello,

> I have tried the following, but it just seems to redirect all traffic to the
> local firewall:
> iptables -t nat -A POSTROUTING -o eth1 -s 192.168.10.2 -j SNAT --to
> 213.249.230.206

	1. -o = output interface. Your local network is connected to eth1,
wright? And you want to NAT all connections from 192.168.10.2 to
internet as 213.249.230.206, wright?
iptables -t nat -A POSTROUTING -o eth2 -s 192.168.10.2/32 -j SNAT
--to-source 213.249.230.206

> iptables -t nat -A PREROUTING -i eth2 -s 213.249.230.206 -j DNAT --to
> 192.168.10.2

	2. -s = source. You want redirect the traffic that comes from the
internet which destination is 213.249.230.206 to your internal pc
192.168.10.2, wright? 
iptables -t nat -A PREROUTING -i eth2 -d 213.249.230.206 -j DNAT
--to-destination 192.168.10.2


Regards,
-- 
--
Alejandro Flores
http://www.triforsec.com.br/
http://www.defenselayer.com/

Re: Very basic question

[Jose Maria Lopez]

El vie, 24 de 09 de 2004 a las 12:28, coding@digital-data.co.uk
escribió:
> Hi,
> 
>             I am very new to trying to use iptables and was wondering if
> someone could help me out with what I should do to solve my current problem.
> 
> I have a PC with 3 ethernet cards, one is connected to the internet (eth2).
> I want to use network translation to forward all requests to a pair of
> static IP addresses I have to particular locales on an internal network
> (which is accessed through eth1).
> 
> Ie forward all incoming traffic on eth2 going to address 213.249.230.206 to
> 192.168.10.2 on eth1.
> 
>  
> 
> I have tried the following, but it just seems to redirect all traffic to the
> local firewall:
> 
>  
> 
> iptables -t nat -A POSTROUTING -o eth1 -s 192.168.10.2 -j SNAT --to
> 213.249.230.206
> 
> iptables -t nat -A PREROUTING -i eth2 -s 213.249.230.206 -j DNAT --to
> 192.168.10.2
> 

Just change the -s for -d, because it's a destination IP.

>  
> 
> What am I doing wrong?
> 
>  
> 
> Tom 
> 
>  
-- 
Jose Maria Lopez Hernandez
Director Tecnico de bgSEC
jkerouac@bgsec.com
bgSEC Seguridad y Consultoria de Sistemas Informaticos
http://www.bgsec.com
ESPAÑA

The only people for me are the mad ones -- the ones who are mad to live,
mad to talk, mad to be saved, desirous of everything at the same time,
the ones who never yawn or say a commonplace thing, but burn, burn, burn
like fabulous yellow Roman candles.
                -- Jack Kerouac, "On the Road"