SLES 10 firewall

[maged67]

I am trying to setup a firewall and redirecting traffic to an internal server, here is what I have:

SUSE server with 2 NIC, the first nic is 192.168.113.5 connected to the internal network and the second nic is 192.168.0.3 connected to internet router.

I want to route the smtp traffic on port 25 to/from the mail server 192.168.113.21.

I also want all the users to connect to the internet through the SUSE proxy server thru the nic 192.168.113.5

There is one PC on the network that should have unristricted access to the internet and maqurate through the firewall for example the 192.168.113.11 should have unristricted access to the internet.

What is the best solution for the above case, should I use rinetd or there is another way to do it int YAST firewall

Thanks