http://theillustratednetwork.mvps.org/RemoteDesktop/Multiple_PC_RD.html

Access Multiple Windows XP Pro Remote Desktops
Behind a Firewall/NAT/Router

Background

Access to multiple PCs that are behind a firewall, NAT or router is fairly easy to configure if the user can forward or redirect TCP ports to the target PC's static LAN IP addresses. The examples illustrate access to four (4) XP Pro PCs behind a Linksys BEFSR41 Etherfast Cable/DSL Router.

Port Redirection Method (Option 1) - Preferred

Port Redirection Configuration

In the following example the four (4) PCs have been configured to listen on the default listening port detailed as follows.

The Linksys router can be configured to pass Remote Desktop Client call requests to multiple PCs on the private LAN. This method illustrates a port forwarding/redirection scheme to multiple PCs that are each listening on the default port. Note that the Linksys Router must have UPnP enabled. Select UPnP Forwarding while on the Forwarding page.

UPnP Port Forwarding for Remote Desktop access to multiple PCs

Registry Change Method (Option 2)

IMPORTANT: This procedure contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article numbers to view the Microsoft Knowledge Base articles:

256986 - Description of the Microsoft Windows Registry

322756 - HOW TO: Back Up, Edit, and Restore the Registry in Windows XP.

To change the Remote Desktop Listening Port reference the Microsoft Knowledge Base Article Q306759 . Note the host XP Pro machine that the listening port was changed on MUST BE REBOOTED in order for the registry change to take effect. Read Microsoft Knowledge Base Article Q304304 for instructions on how to configure the Remote Desktop Client to call using an alternate port.

Port Forwarding Configuration

In the following example the four (4) PCs have been configured to listen on different ports detailed as follows.

The Linksys router can be configured to pass Remote Desktop Client call requests to multiple PCs on the private LAN. This method illustrates a port forwarding scheme to multiple PCs that are each listening on a different port.

Port Forwarding for Remote Desktop access to multiple PCs

Call Scheme (Options 1 and 2)

Calling  for Remote Desktop access to multiple PCs is accomplished by appending the Listening Port Number to the public IP address or alias of the router. If the firewall/router is configured correctly, the call will be successfully passed to the appropriate PC. Examples using DNS2Go are:

Call PC1 using the IP method:

12.34.56.78 or 12.34.56.78:3389

Call PC2 using the IP method:

12.34.56.67:3390

Call PC3 using the alias method:

YourAlias.dns2go.com:3391

Dynamic DNS Services (Some free, some not)

Dynamic DNS Network Services

No-IP.com

DNS2Go - Dynamic DNS Solution $$$$$

TZO.com $$$$$

Notes

1. Linksys router configuration pages illustrated are current as of the Linksys v1.42.7 firmware release.

2. The Linksys router must be configured so SPI is disabled on the Filters configuration page.

3. In the preceding examples, the specific ISP assigned public IP address should be substituted in place of the example IP. Similarly, the assigned alias should be substituted for the example alias.

4.  Remote Desktop must be enabled on each PC.

5. Static IP addresses assigned to networked XP Pro PCs.

6. Windows XP UPnP functionality is installed.

Windows XP Remote Desktop Resources

The Remote Desktop How-To

Jeffrey Randow's Windows XP Remote Networking page.

Cannot connect to another computer using Windows Remote Desktop after installing Norton AntiVirus 2005

Situation:

After you install Norton AntiVirus 2005, you cannot connect to another computer by using the Windows XP Remote Desktop software.

Solution:
To fix the problem, create a program rule in Internet Worm Protection for Mstsc.exe and Svchost.exe located in C:\Windows\System32. Read the following section for detailed instructions.

To create a new program rule

1. Start Norton AntiVirus.
   If Norton AntiVirus is installed as part of Norton SystemWorks or Norton Internet Security, then start that program.
2. Click Options.
   If you see a menu, click Norton AntiVirus.
3. In the left pane, click Internet Worm Protection.
4. In the right pane, click Program Control.
5. Click Add.
6. Navigate to C:\Windows\System32, and click Mstsc.exe.
7. In the next dialog box, in the drop-down menu, click Permit.
8. Repeat steps 3 through 7 for Svchost.exe.
9. Click OK.