Thanks Wez, Let me rephrase my question then. Assume the viewer and server communicate over a low quality (and low bandwidth) network. What are the scenarios (other than unplugging the network cable) where the client "goes fishing" with an info/error message but the server continues running the session until the idle timeout tells it to dispose it? And how can one guard (terminate the session earlier than the idle timeout) against them happening?
-nik -----Original Message----- From: James Weatherall [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 08, 2006 5:51 AM To: Kolev, Nik; [email protected] Subject: RE: How to terminate VNC sessions immediately at network connection drop Nik, The only reason your viewer detects the connection drop is that your computer has had the cable physically removed - it sees this and removes the routing information for that network connection from the TCP stack, then notices that there is now no way to reach your server, and so returns the (wrong, as it happens) error code to VNC Viewer. The server doesn't notice that the viewer computer has been physically disconnected, because no-one tells it - the viewer can't tell it, because it's been disconnected from the network. The only part of the system that *could* tell it is the switch to which the viewer computer was connected, assuming it knows that the viewer computer does not have other network connections. The only practical way to implement this sort of functionality is with a regular "ping" and timeout combination, but this still won't give you instantaneous disconnect, and may lead to disconnects in the event of network delays, etc. Regards, Wez @ RealVNC Ltd. > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Kolev, Nik > Sent: 07 March 2006 21:19 > To: [email protected] > Subject: How to terminate VNC sessions immediately at network > connection drop > > Hi, > > I've set up a non-persistent vnc (v. 4.1.1) session through inetd (on > Solaris and Linux) and using vncviewer (v 4.1.1.) to connect from > Windows workstations. > > The vncviewer is configured to not "Offer To Automatically Reconnect". > When I unplug the network cable of the windows workstation I expect > and get a vncviewer info prompt saying "read: Connection reset by peer > (10054)". What I also expect to happen is that the corresponding > server > (Xvnc) detects this and terminates the session running on the server > side immediately. Unfortunately this does not happen. The session only > gets terminated after the idle timeout (default: 3600 secs). > Is there a > way to enforce this to happen? > > Here's how I start Xvnc on Solaris through inetd: > /usr/local/bin/Xvnc -inetd -securitytypes=none -desktop remote-user > -depth 16 -geometry 1024x768 -nolisten named -query localhost -once > 3>/dev/null > > Thanks, > -nik > > > Confidentiality Notice > This e-mail (including any attachments) is intended only for the > recipients named above. It may contain confidential or privileged > information and should not be read, copied or otherwise used by any > other person. If you are not a named recipient, please notify the > sender of that fact and delete the e-mail from your system. > _______________________________________________ > VNC-List mailing list > [email protected] > To remove yourself from the list visit: > http://www.realvnc.com/mailman/listinfo/vnc-list > Confidentiality Notice This e-mail (including any attachments) is intended only for the recipients named above. It may contain confidential or privileged information and should not be read, copied or otherwise used by any other person. If you are not a named recipient, please notify the sender of that fact and delete the e-mail from your system. _______________________________________________ VNC-List mailing list [email protected] To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list
