Question : Problem: Unable to access PC via radmin from external IP

Hello, please bear with me through my explaination.
I have a Windows SBS 2003 server which has 2 network adapters in it, one of which gives access to the internet and the other gives access to the network, therefore the server acts as a firewall for the PC's on our network.
The IP address' are as follows
Adapter for the internet has IP of 192.168.16.2, router is 192.168.16.1
Adapter for the network has IP of 192.168.88.1
 This setup is all working fine, however, I have a problem whilst using a program called Remote Administrator (Radmin.com) to access this server from another office.

I am using a netgear router at the moment (please be aware I have also tried a Draytek Vigor router which I have used many many times and setup for Radmin lots of times too and I am having the same problem), I have configured a service within that router (basically this is a port name and number) I have called the service radmin and I have assigned it port number 4899 which is the correct default port for radmin. I have then gone into the firewall section of the router and told it to use the Radmin service I just created and point anything coming in on port 4899 to direct to Local IP address of 192.168.16.2.

The next step then is to shut off the internal firewall on windows (or create an exception for port 4899), in this case I have disabled the windows firewall service.

I then start up the Radmin server file (r_server.exe) on my SBS server.
Next, from another office I use the Radmin viewer and put in the static IP address of the building (the presentation IP), this then goes to the router in the office which I am trying to access which checks the port and passes the connection onto 192.168.16.2 and viola I have remote access.

Or not so in this case.

I can see in the log of the router that it has seen the incoming connection and forwarded it onto 192.168.16.2 on port 4899, but I fail to get access.

I have tried from another PC in the same building as the server, accessing the server via radmin from the local IP address of the server and that works fine so I know it isnt a firewall issue on the server but I have no idea what else it could be causing this problem, like i said before I have tried another router which I am very fimiliar with and am 100% it isnt a router issue. Could anybody please shed some light on where I'm going wrong here as im lost.

Thanks very much for reading,

Mark

Answer : Problem: Unable to access PC via radmin from external IP

Despite trying everything we still could not get access to the server. In the end we resolved it by using Logmein.

But thanks for all your help