WAN to LAN using NAT

[GWINTO]

Our external connection is via a cable mobem, this is connected to a multihomed 2k server.
Intrenal NIC 10.0.0.4 External 192.168.0.3 (connected to a router to the WAN). The router port forwards 25, 80, 110 to 192.168.0.3, we then want the packets sent out on the LAN to reach 10.0.0.3 (Our exchange server). we can send out e-mails fine but cant recieve them. Prior to this the exchange server was on the multihomed machine and worked fine.

 

[SgtB]

How is NAT configured on the 2k machine? The incoming packets on ports 25 and 110, need to be translated to the exchange server. All outgoing packets through 25 and 110, need to be translated to the external IP on the 2k machine.

That's how I'd do NAT anyway. So what are you doing with NAT right now?

 

[GWINTO]

Every thing is standard 2 nics one internal one external, what we need is a walk through of how to configure the server to forward from the external to the internal.

 

[SgtB]

All you need to do is enable IP forwarding on the server (in TCP/IP properites). Any packets that come to one interface will be forwarded to the other interface.

Is this all you're asking?