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UltraVNC SC doesn't work in a VPN connection

Single Click discussions / bugs
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decibel83
Posts: 7
Joined: 2007-10-03 13:28

UltraVNC SC doesn't work in a VPN connection

Post by decibel83 »

Hi.

I created my personal version of UltraVNC SC.
I use it without any problem every day, but it doesn't work when I try to use it on a VPN connection on the server (the computer which accept the connection from the SC program - the controller computer, not the controlled).
This is a notebook connected to the Internet with an UMTS card and it is also connected with my server (which has a static IP address) with a VPN connection (PPTP).
On the VPN side it has a static IP address (192.168.1.191), so I created on the server a DNAT rule which forwards the incoming calls from the my.public.ip.address:5591 to 192.168.1.191:5500 on the VPN connection.

When I try to connect from UltraVNC SC to my notebook I get the following error on my notebook (the one which has UltraVNC Viewer in listen mode):

Code: Select all

Connection failed - Error reading protocol version
Possible causes:
- You've forgotten to select a DSMPlugin and the Server uses a DSMPlugin
- Viewer and Server are not compatible (they use different RFB protocoles)
- Bad connection
I repeate, the connection work whithout any problem with the same SC program connecting to the same station not connected with a VPN connection, so the problem isn't the DSMPlugin nor the protocols.

What's the problem? Could you help me, please?
I need to make some assistance to my customers when I am out of my office too, using my UMTS card.

Thank you very much!
Bye.
bevtech
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800
Posts: 2168
Joined: 2005-08-03 14:07
Location: Pennsylvania, United States

Re: UltraVNC SC doesn't work in a VPN connection

Post by bevtech »

That would depend on the vpn connection, type of tunnel it is and how it is structured..


I would try to use port 80 or another common port with your single click connection and see if it works.

Need to change the helpdesk.txt ::80 and change the commandline of the listener to -listen 80
Bevtech

Windows XP Home, Pro SP2, Windows 2003 SBS server SP2(EN), Windows Media Center Editon 2005,Windows Vista Home Prem.,Fedora Core 6,Win9X, PChelpware Rel 1.0,
UVNC V 1.0.8.2

User not developer..;)
redge
1000
1000
Posts: 6797
Joined: 2004-07-03 17:05
Location: Switzerland - Geneva

Re: UltraVNC SC doesn't work in a VPN connection

Post by redge »

VPN software or hardware ? up to date, fix ?
stack tcp ip need to be smaller for VPN
reduce mtu from 1500 to 1492
UltraVNC 1.0.9.6.1 (built 20110518)
OS Win: xp home + vista business + 7 home
only experienced user, not developer
decibel83
Posts: 7
Joined: 2007-10-03 13:28

Re: UltraVNC SC doesn't work in a VPN connection

Post by decibel83 »

redge wrote:VPN software or hardware?
VPN software with poptop (pptpd) on Linux Debian.
up to date, fix ?
Yes, it is the latest version available.
stack tcp ip need to be smaller for VPN
reduce mtu from 1500 to 1492
How I can setup it? On the VPN server or the VPN client?

Thank you very much!
redge
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1000
Posts: 6797
Joined: 2004-07-03 17:05
Location: Switzerland - Geneva

Re: UltraVNC SC doesn't work in a VPN connection

Post by redge »

> How I can setup it? On the VPN server or the VPN client?
DrTCP
http://www.dslreports.com/drtcp

at VPN client
UltraVNC 1.0.9.6.1 (built 20110518)
OS Win: xp home + vista business + 7 home
only experienced user, not developer
decibel83
Posts: 7
Joined: 2007-10-03 13:28

Re: UltraVNC SC doesn't work in a VPN connection

Post by decibel83 »

I changed the MTU to 1492 and 1400 but it doesn't work... :-(
redge
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1000
Posts: 6797
Joined: 2004-07-03 17:05
Location: Switzerland - Geneva

Re: UltraVNC SC doesn't work in a VPN connection

Post by redge »

restart required.
UltraVNC 1.0.9.6.1 (built 20110518)
OS Win: xp home + vista business + 7 home
only experienced user, not developer
decibel83
Posts: 7
Joined: 2007-10-03 13:28

Re: UltraVNC SC doesn't work in a VPN connection

Post by decibel83 »

Yes, I restarted after any changes I made but it doesn't work...
redge
1000
1000
Posts: 6797
Joined: 2004-07-03 17:05
Location: Switzerland - Geneva

Re: UltraVNC SC doesn't work in a VPN connection

Post by redge »

i'm sorry, out of idea.
UltraVNC 1.0.9.6.1 (built 20110518)
OS Win: xp home + vista business + 7 home
only experienced user, not developer
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