nat problem.

["umar" <vramnarayan@triniti.com>]

Hi, 
 
Trying out  a very simple configuration of a firewall here, but having some problems.
The firewall  has two NIC's and have enabled ip forwarding. 

I want the internal machines to connect to the internet,  So have enabled NAT : 
Runing squid - transparent proxy on port 3232. Clients have been onfigured to connect to internet directly. 
eth0 is my external interface.
 
Following are the nat rules conigured on the firewall
 
iptables -t nat -A PREROUTING -i eth0  -p tcp --dport 80 -j REDIRECT --to-port 3232
 
iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to-source x.x.x.x ( public IP of the other netwrok card )

I can ping to the gateway ( private IP ) and the other network card havng the public IP , but nothing beyond that, Why ?? 
And my clients are also not able to connect to the internet ?? 
I have tried removing the first rule and disabling squid, so that clients could connect to the intenet directly. 
That also failed, and the result is the same. All the default poilicies of all rules are set to ACCEPT.

Runing rh 7.2 with 2.4.7-10 kernel.

Please help. 

Warm Regards, 
Kumar.