Re: DNAT Rules.

[Edmundo Carmona <eantoranz@gmail.com>]

I'd say:

iptables -t nat -A PREROUTING -i eth1 -d 1.2.3.4 -p tcp --dport 80 -j
DNAT --to-destination 10.1.1.2
iptables -A FORWARD -p tcp --dport 80 -d 10.1.1.2 -j ACCEPT

also:
iptables -A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT

IMHO... well... you can delete the H from IMHO... but that's just me! :-)

On 9/25/05, Vincent Blondel <vincent@xtra-net.org> wrote:
> Hi,
>
> I am trying to configure next set up so a public host can connect to my web server located in a dmz.
>
>                   -----------------------
>   public host --> |  eth1        eth2   | -->  web server
>     x.x.x.x       | 1.2.3.4    10.1.1.1 |      10.1.1.2:80
>                   ----------------------
>
> As far as I can understand, this typically corresponds to a mix of DNAT, SNAT and FORWARD rules. Below you can find the
> rules I have configured until now.
>
> #####################################################################
>
> # Enable ip forward
> echo 1 > /proc/sys/net/ipv4/ip_forward
>
> # Unlimited traffic on the loopback interface
> iptables -A INPUT  -i lo -j ACCEPT
> iptables -A OUTPUT -o lo -j ACCEPT
>
> # Set the default policy to drop
> iptables --policy INPUT   DROP
> iptables --policy OUTPUT  DROP
> iptables --policy FORWARD DROP
>
> iptables -t nat --policy PREROUTING  DROP
> iptables -t nat --policy OUTPUT      DROP
> iptables -t nat --policy POSTROUTING DROP
>
> iptables -t mangle --policy PREROUTING  DROP
> iptables -t mangle --policy POSTROUTING DROP
>
> iptables -t nat -A POSTROUTING -o eth1 -j SNAT --to-source 1.2.3.4
>
> iptables -t nat -A PREROUTING -i eth1 -p tcp --sport 1024:65535 -d 1.2.3.4 --dport 80 -j DNAT --to-destination 10.1.1.2
> iptables -A FORWARD -i eth1 -o eth2 -p tcp --sport 1024:65535 -d 10.1.1.2 --dport 80 -m state --state NEW -j ACCEPT
>
> iptables -A FORWARD -i eth2 -o eth1 -m state --state ESTABLISHED,RELATED -j ACCEPT
> iptables -A FORWARD -i eth1 -o eth2 -m state --state ESTABLISHED,RELATED -j ACCEPT
>
> #####################################################################
>
> But the problem is that it doesn't work and I don't know why ? So can somebody help me to solve this problem ?
>
> Regards
> Vincent
>
>
>