VNC Remote Viewing into LAN

William Hooper
Fri Jul 25 22:44:00 2003

msn said:
> Hi William
> Thanks for your reply on VNC-list - I just need some clarification.

No problem, but please send responses to the list.

> With VNC Viewer support you said "forward the traffic to
>" and I tried to put this into the router's Virtual
> Server page ("Virtual Hosting which is used to allow Internet users access
> to LAN Services") but it only allows the following fields:
> Name of Port - I set to Port 1
> Private IP - set to (it won't allow :5900 into this field
> due to length constraint)
> Protocol TCP/UDP/Both - set to TCP
> Private Port - set to 5800
Private Port needs to be 5900

> Public Port -  set to 5900
> Is this doing what you said?

If you also want to use the java viewer, you will need to set up another
port forward using:
Private Port - 5800
Public Port - 5800

> Public IP Address of Router is
> and when I use VNC Viewer with (or 5800) I get null
> response.

Because you are trying to talk to the HTTP port (5800).

> As an experiment I tried setting the port routing to the VNC server which
> is at and  then used Internet Explorer with the address
> and I got the VNC Authentication window but when
> I entered the password I had set in VNC I got message
> ""

Because to use the Java viewer you need to forward *both* the HTTP port
(5800) and the RFB port (5900).

> When I tried VNC Viewer with this setup I still got null response.
> Would appreciate your further advice.
> Regards, Bill Pickering

You can to some extent play around with what external port you want to
use, but the internal ports need to be the ones that VNC is listening on.

William Hooper