Update: UltraVNC 1.4.3.6 and UltraVNC SC 1.4.3.6: viewtopic.php?t=37885
Important: Please update to latest version before to create a reply, a topic or an issue: viewtopic.php?t=37864

Join us on social networks and share our announcements:
- Website: https://uvnc.com/
- GitHub: https://github.com/ultravnc
- Mastodon: https://mastodon.social/@ultravnc
- Facebook: https://www.facebook.com/ultravnc1
- X/Twitter: https://twitter.com/ultravnc1
- Reddit community: https://www.reddit.com/r/ultravnc
- OpenHub: https://openhub.net/p/ultravnc

Control local port of WinVNC & Vncviewer

Post Reply
vincentt
8
8
Posts: 14
Joined: 2011-07-28 23:08

Control local port of WinVNC & Vncviewer

Post by vincentt »

Hi,

I have installed UltraVNC on a Windows 7 system, the VNC server configured to run on port 5900 and running as an application on Machine Server IP 192.168.100.10. When no user is connected, running netstat -a -n, gives me
"TCP 0.0.0.0:5900 0.0.0.0 LISTENING" which is good, and when a user is connected from say an IP 192.168.200.20, the entry now becomes - "TCP 192.168.100.10:5900 192.168.200.20:44501 ESTABLISHED" which is also good. And similarly the netstat entry on the client looks something like "TCP 192.168.200.20:44501 192.168.100.10:5900 ESTABLISHED". This is all expected and good.

The question I have is, whether there is a way to restrict the Local port opened ie 44501 in this case. The TCP port is randomly given and we have an issue there as the local port opened ranges from 44000 all the way to 60000+. We have VNC installed on our customer client machines to help us access the machine for trouble shooting. I do understand this is not directly a VNC question, its more to do with Windows, but is there a way to do some kind of restriction on Ports?

The issue is when this existing connection is closed, and another connection is made, the port number is different and random over a wide range.

Any help in this regard would be helpful.

thanks,
Vincent
User avatar
Rudi De Vos
Admin & Developer
Admin & Developer
Posts: 6832
Joined: 2004-04-23 10:21
Contact:

Re: Control local port of WinVNC & Vncviewer

Post by Rudi De Vos »

This is part of the TCP protocol, and can't be changed.
vincentt
8
8
Posts: 14
Joined: 2011-07-28 23:08

Re: Control local port of WinVNC & Vncviewer

Post by vincentt »

Hi Rudi,

Thanks for your reply, I did guess that, but your reply would help me to officially close a case!

Sorry about the delay in replying.

Regards,
Vincent
Post Reply