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I need to know how to connect to a VNC server that is behind a router or firewall, with a VNC client

Posted on 2007-03-24
Medium Priority
Last Modified: 2013-11-30
I need to know how to connect with a VNC Client,  t to a XP box that is behind a router or firewall, with a VNC server running on it (UltraVNC for now).  I have been able to connect successfully to any box with a static IP with VNC server, but need to know how to configure and make this work with a XP box that is behind a router or firewall, and that has a internal IP like IP).                         I need to know how to connect to a VNC server that is behind a router or firewall, with a VNC client
Question by:Mike Treat
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LVL 32

Accepted Solution

LucF earned 2000 total points
ID: 18786390
Hello avbmiket,

In VNC, you can set the IP address to listen to, by default this is port 5900.
By forwarding this port to the host you want to connect to on the used router you can still use VNC.
How to forward ports for realVNC can be seen through Just select the router you're using and you'll get step-by-step instructions.


LVL 32

Expert Comment

ID: 18786400

I misread your question, for UltraVNC, please visit, the default port is still the same though. The explanation is just more clear.


Expert Comment

ID: 18786970
It sounds to me like you would be a good canidate for Single Click VNC. The client inititates the connection to your server. Single click VNC server uses port 5500 by default. Set your router to forward port 5500 to your VNC server. There is a small program you setup for your clients to download and then connect to your server.
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Expert Comment

ID: 18817253
VNC port by default is port 5900
not 5500

The standard VNC Display numbers, 0-99, correspond to TCP ports 5900-5999. VNC Server will accept connections on port number 5900 by default, which equates to VNC display number 0 (zero). The port number for VNC Server to use can be set to any other available port number, even ones outside the 5900-5999 range.

Basically just DMZ the pc out that you wanna connect to or setup port fowarding on your router to hit 5900 and redirect it to the lan Pc with VNC running.
Also use vnc 4.1.2, anything below that and you can get hacked, i've seen and tested the exploit myself,

Expert Comment

ID: 18835533
try hamachi( and then ips given by it to connect

Expert Comment

ID: 18836745
Hi Kane...

I was referring to Single Click click VNC and not VNC. If you would like more information on Single Click VNC you may want to look it up.
LVL 32

Expert Comment

ID: 18969668

Take your pick, I think my comment solved avbmiket's comment without any problems. He/she might have gone for another option. Even though I never used it myself and honestly don't know how it works as I tend to use other solutions myself, http:#18786970 could give a solution with "Single click VNC", another explanation on how VNC works was posted at http:#18817253
I would leave out http:#18835533, it was a terrific suggestion, but not for the question asked. Hamachi is a very firewall friendly VPN client, but should not be used in combination with VNC or RDP as it'll slow down things to a crawl.

As I tried to say by my first three words; it's up to you to decide which comments you think might be the best in answering this question. I'm just giving my oppinion on all comments an mean no disrespect to any of them.


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