Remote Desktop

Patrick Doyle wpdster at
Fri Aug 6 16:10:45 UTC 2010

On Fri, Aug 6, 2010 at 11:15 AM, Kipton Moravec <kip at> wrote:
> I am having problems with Remote Desktop running on a computer behind a
> firewall.
I presume you mean you want to connect to a Ubuntu (or other Linux
distro) server from a Ubuntu (or other Linux) client using VNC -- not
to a Microsoft Windows machine using Microsoft Remote Desktop.  If my
assumption is incorrect, then the rest of this response probably won't
help much.

> I have opened up port 5900 and pointed it to the IP address of the
> remote computer I want to connect to. Is it TCP or UDP?  I have tried
> both and can not get it to work.
VNC uses TCP

> Both computers are behind NAT Firewalls. If I want to initiate a remote
> desktop from my Home computer to the Remote Computer, I only have to
> have port 5900 open on the firewall to the remote computer.  It does not
> need to be opened on the firewall of the Home computer right?

> It does work on my home network where I do not have a firewall between
> the computers.  I am wondering if there are other ports it uses like
> telnet, SSH or FTP. I have those ports open and working, but the
> firewall has them on non-standard port numbers for the Internet side.
nope.  VNC just uses port 5900 (or 5901 if you connect to :1, 5902 for
:2, etc...)

If you configure your home firewall to route port 5900 to port 5900 on
the destination computer, then you should be able to point your VNC
client (i.e. Ubuntu remote desktop connection) to the IP address of
your firewall and it should just work.

It should even just work if you do that from within your home network,
although that depends a little on the firewall.

Do you know the IP address of your firewall?  Not the
address, but the address it was assigned by your ISP.

That's the address to which you should be connecting from the outside.


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