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Windows RDP access to multiple computers with D-Link DSL-2740B router

We have a D-Link DSL-2740B (Rev_E) router and a static IP address.
I have set up port forwarding to connect to different computers on our LAN from the outside.
The server is Windows 2008 R2. The default RDP port, 3389 points to the server's internal IP and this works, meaning we can connect to the server from an external PC on Windows XP Pro with Windows Remote Desktop, no problem. We cannot connect to other computers on the LAN. The setup is like this :
Name          Address          External Port    Internal Port        Protocol     WAN Interface
SERVEUR    3389               3389                   TCP            ppp0_1
POSTE1  3396               3396                   TCP            ppp0_1
POSTE2  3395               3395                   TCP            ppp0_1

We can connect with RDP within the LAN to all the computers, no problem

From the outside we can connect with RDP to
or 217.xxx.xxx.49:3389 (specifying the default RDP port) - no problem,

but we cannot connect to, for example:

I tried disabling the firewall and the antivirus - that didn't work
I tried putting the server in a DMZ - that didn't work
I tried putting a specific computer in the DMZ - that didn't work

This is something that worked for us "before" - i.e. it worked with our old modem-router provided to us from our ISP (Orange.fr) - the old one was a Livebox Inventel Pro. Unfortunately it broke down so the ISP replaced it with their new model. The new model didn't work for the external RDP (and it's not possible to get an old model anymore). So we assumed that getting a brand new D-Link router would solve the problem...
I have also tried using the Windows 2008 RDP Web Access, which works internally but not externally - we keep getting the same error saying it's impossible to connect to the PC in question
1 Solution
Are the client computers setup to listen for RDP on port 3396, 3395, etc? If not, you have to change the ports that RDP listens on:

http://support.microsoft.com/kb/306759 (don't use the 'Fix it for me' tool, do it manually via regedit).


jdailey59Author Commented:
This worked perfectly before with our old router without having to change the RDP listening port on each individual client. I went ahead and tried this anyway on one client, modifying the registry manually, then rebooting it, but it still doesn't work - sorry :(  - but thank you for the suggestion
I'm not familiar with your particular D-Link model, but the D-Link I have had better success using the "NAT - Virutual Servers" feature rather than port mapping/port forwarding. If you have NAT enabled on the router, you can go to the Advanced tab and configure Virtual servers for each of your RDP hosts. Just configure the External Port Start - End and Internal Port Start - End with the custom RDP port for each PC, i.e. Start 3396 End 3396

This worked for me hope it helps.

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jdailey59Author Commented:
NAT is enabled on my router and in the manual I see that Virtual Servers is supposed to be in the Advanced menu, just under Firewall Settings, but it's not there - do you know where I can find it?
You might check D-Link's website for firmware updates. It appears there was one update that involved NAT support. Maybe start here:

jdailey59Author Commented:
I just spoke with D-Link tech support and the Virtual Server doesn't exist for my model anymore, and it's not possible to downgrade the firmware to get it back. They now tell me that Port Forwarding is the only option available now for the DSL-2740B and that if that doesn't work then I'd need to get a different (e.g. more expensive) VPN router.
I've done a lot of this.... you need to set all the internal ports to 3389, as this is the default ports on the servers themselves.
jdailey59Author Commented:
This port forwarding solution for external RDP works for my router :
D-Link DSL-2740B Rev EU_5.17
Example :
Name External Port  Internal Port  Protocol
Server    3389             3389             TCP
PC1         3396             3389             TCP
PC2         3397             3389             TCP
Then access each individual machine on RDP with the public IP (ours is static)
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