iptables and NAT

[Jatin K]

On Tuesday 25 January 2011 06:16 PM, Jorge Fábregas wrote:
> On 01/25/2011 08:17 AM, Jatin K wrote:
>> but server is not forwarding the packets to the web server
> Besides the NAT rule, you'll need a forward rule (as that traffic is not
> for the machine hosting the firewall).  I think you'll need something like:
>
> iptables -A FORWARD -d 192.168.131.131 -p tcp --dport 80 -j ACCEPT
>
> ...and of course check the firewall on the web-server to allow incoming
> TCP/80.
>
> --
> Jorge
I've done the following

[1]    echo 1 > /proc/sys/net/ipv4/ip_forward     ( enabled ip forwarding )


[2]    iptables -A FORWARD -d 192.168.131.131 -p tcp --dport 80 -j ACCEPT

[3]    iptables -t nat -A PREROUTING -d xx.xx.xx.xx -p tcp --dport 80 -j 
DNAT --to-destination 192.168.131.131

port 80 is opened on the web server  I'm able to access the web -page 
from internal systems as well as from the firewall it self through elinks
but not able to access the web-page from Internet ( means firewall 
system is not forwarding the packets to the web server )

I've also tried following rule in firewall for SNAT

iptables -t nat -A POSTROUTING -s 192.168.131.131 -j SNAT --to-source 
xx.xx.xx.xx

but it fails

what do  I need to check further .... what other configuration do I need ??

Thnx

-- 
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   ^ ^  Jatin Khatri
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