Scenario : Windows 2008 R2 SP1 Spanish
The whole behaviour is supervised via iLO on a HP server.
UltraVNC : 22.214.171.124
Installed mirror driver. Activated SystemHookDll and Mirror Driver.
On startup, Windows Server is on the CTRL-Alt-Supr screen.
Connect via UltraVNC. Connection succeeds, but terribly slow. I press CTRL-Alt-Supr, type user/password with UltraVNC and Windows begins the user login. UltraVNC viewer loses connection, and the desktop is no more redrawn. In iLO I can see the desktop, and the UltraVNC icon appears in tray, in yellow. It says Winvnc - <IPs> - <EQName> - Service - vnchook. The viewer is not getting any updates. The desktop is not being drawn. If I disconnect the viewer, the server hangs, and it stays in yellow. The CPU keeps on a high state.
If I try to reconnect, I never get a connection. UltraVNC server keeps crashing and restarting. It logs an incoming session in Windows log, then crashes, and restarts.
If I restart the service, then randomly I get the same crash behaviour, or a total stable server after a few attemps. Before crashing, I can see with iLO, that the server says on tray : Winvnc - <IPs> - <EQName> - Service - driver. Then crashes (disappears) and restarts in a loop. No logs in Windows about the crash.
Maybe a not closed connection in the crashed server is the cause?
Sometimes when a connection is made, I can see briefly the server is connected with vnchook, then it changes to driver. Maybe the swapping, if a connection is hung, is causing the issue? I don't know if the server is really swapping modes, or it is just an misinfo issue.
If I logout the user, the connection does not drop, and it lets me relogin with CTRl-Alt-Supr. As soon as the desktop is drawn, the same issue appears. The server hangs. The viewer never gets the desktop image. The server hangs in yellow, high CPU, etc, etc.
When server hangs, I can see with TCPview 2 connections to the server. One that is saying CLOSE_WAIT, and another one. So one connection is hung. When the connection is purged by the OS, the ultravnc server keeps on yellow, by few seconds, then it crashes, and restarts in blue. Then, and only then, I can stablish a correct connection to the server.
Is the server restarting/crashing, when we go from the CTRL-Alt-Supr screen to the user desktop? Is the server not closing the connection when doing that?
In brief. When logging out, the connection is not lost, but it becomes terribly slow (swapping driver/hook?). At least I can manage the server. As soon as I login, the viewer never gets the desktop. Sometimes it crashes and restart, and I can see 2 connections (one in CLOSE_WAIT state and one STABLISHED), but never really connects. Sometimes it does not crash, and I can see only one connection, but the viewer never gets the desktop. If I close the viewer, the connection appears as CLOSE_WAIT, but cannot reconnect ever. Most of the times, when the connection is purged by the OS, the server crashes and it restarts, and then I can connect correctly. But I have observed too at least one time, that the server has not crashed whe the OS purged the connection, but then, I cannot reconnect.
So the working scenario, in this case is: all pending connections closed, and restarted server, it is OK. If the server is restarted when connections are hung, then it is a no go.
The question is: why are the connections hung?
It is driving me nuts, as I cannot connect after loggin in, and I have to wait a prudential time, to let the OS close connections, and hope that the server has crashed/restarted in a clean state. If not, then I have to connect/disconnect again and make the wait again.
I have described as much info as I can collect, in hope that it can give you any clue.