Remote Desktop Between Ubuntu/Linux and Windows, Part II
Configuring Your Router

Eric Geier
Monday, January 26, 2009 11:43:16 AM
In Part I
of this two-part tutorial we discovered options on remoting between Linux and
Windows machines. Plus we setup the VNC solution on each platform. Now we'll
continue by configuring our router for connections over the Internet.
Additionally, we'll see how to encrypt the connections and how to remote into
the native display. Let's get started!
Telling your router to forward
Before you can remotely connect to your computer from another location over
the Internet you must properly configure your router. The router acts as an
distributor for your network traffic. If you don't tell your router where to
forward the remote desktop traffic, it won't do anything and your remote
connections won't work. Thus you must create a port forward or virtual server
entry for the appropriate ports to the IP address of the desired computer. Then
when incoming traffic on those ports comes from the Internet, your router will
forward it onto the computer and the remote desktop server will response.
Depending upon the protocol, use one of the following ports (or port ranges):
- RDP uses TCP port 3389
- VNC uses TCP port 5900+ (Each remote connection to a server uses a
different port; display 1 uses 5901, display 2 uses 5902, etc) It's best to
define a port range when creating the forward or virtual server entry, such as
5900 - 5905.
You want to bring up the web-based configuration page for your router, by
typing it's IP address into a web browser. Then go to the Virtual Server or Port
Forwarding page. You'll probably have to name the entry, use a combo box to
select the desired computer or manually
enter the computer's IP address, type in the public and private (both are the
same) port or port range, and click Save.
You need to make sure the computer keeps the same IP address on the network.
If available, use the DHCP reservation feature to force the current IP address
to the particular computer. Otherwise you'll have to set your computer's network
adapter with a static IP address.
If you have multiple computers you want to remotely connect to over the
Internet using VNC, you'll need to a create a separate entry for each computer.
Make sure each computer is on a different port, which is represented by the
tunnel or display number shown when you run the vncserver command in Linux, for
example. Also make sure each entry forwards to different IP addresses.
Next: Securing VNC connections »