Error reading protocol version

Waszkewitz Peter (PA-ATMO/EES22) * Peter.Waszkewitz "at"
Tue Apr 27 14:24:00 2004

Trying to connect to a VNC server on a Win2K system through a firewall (over
which I do not have any control) I receive an "error reading protocol version"
message. A packet sniffer shows me that there is a connection established, but
instead of the protocol version RBF something only some 0s are returned.

The firewall is open for the two IP addresses in question on port 5900. I

	telnet IP-address-of-server 5900

and it does connect but echoes nothing (not exactly surprising, considering
the 0s). telnet on other ports rightly refuses connection.

I have tested various scenarios with other machines (blank password, different
default and user passwords, ...) and have not seen this behavior. The packet
sniffer does not show any other port on the server being used than 5900. I
have tried two different machines with three different network cards as client
and always have the same effect.

Does anyone have an idea what may cause this behavior?

Peter Waszkewitz