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

Cannot connect, sometimes--why?

Post Reply
EastCoastDB
Posts: 2
Joined: 2013-10-03 17:54

Cannot connect, sometimes--why?

Post by EastCoastDB »

Hi All,

I've got uVNC running on about 20 computers in server mode only. Some are Vista, some are Win7, one is a SBS server, mixed 32&64bit. My problem is that there's no consistency to when I can and cannot connect to these machines--I never know if I'll get a failed connection or not.

I've got all these computers on one subnet with reserved, static IPs. They are either running Windows Firewall or a Kaspersky variant. In each, uVNC is allowed and TCP 5900 is open.

For example, I currently have one machine I can't connect to. I could yesterday. Right now, with that machine sitting beside me, I have turned the firewall on and off, verified that the port was open and the uVNC exception is on the list, and still I can't connect. I don't know how to begin troubleshooting this--can someone please help me? I love uVNC, but if I can't get it to work consistently, I won't be able to keep using it.
User avatar
Rudi De Vos
Admin & Developer
Admin & Developer
Posts: 6832
Joined: 2004-04-23 10:21
Contact:

Re: Cannot connect, sometimes--why?

Post by Rudi De Vos »

It's very hard to answer a general question.
VNC only use one tcp 5900, if that's allowed on both sites the connection is made and at least you get a box for entering the password.

First you need to findout if it's a viewer or server issue.
As you have many servers, you can exclude the viewer if he is still able to connect to another server ( this already limit the search)
On a server not working, you can always try

1) Use a viewer on the same pc as the server ( loopback mode) and see if you can connect. connect the viewer to "localhost".
2) telnet 5900: if you telnet to the vnc port it answer "rfb....
3) activate server logging, perhaps there is someting in it.
EastCoastDB
Posts: 2
Joined: 2013-10-03 17:54

Re: Cannot connect, sometimes--why?

Post by EastCoastDB »

Rudi De Vos wrote:It's very hard to answer a general question.
VNC only use one tcp 5900, if that's allowed on both sites the connection is made and at least you get a box for entering the password.

First you need to findout if it's a viewer or server issue.
As you have many servers, you can exclude the viewer if he is still able to connect to another server ( this already limit the search)
On a server not working, you can always try

1) Use a viewer on the same pc as the server ( loopback mode) and see if you can connect. connect the viewer to "localhost".
2) telnet 5900: if you telnet to the vnc port it answer "rfb....
3) activate server logging, perhaps there is someting in it.
Thanks--I'll look into these today and report back.
Post Reply