Inconsistent Windows 7 RDP connections

[Miguel Goya <mg...@clearedgeit.com>]

Hello,

Running Guacamole 0.9.9, with LDAP extenstion for Active Directory (Windows
Server 2012)  authentication configured.  It is running behind a reverse
proxy.

So I am having an issue establishing connections to certain Windows RDP
machines.  These connections are VMs running in VMware (ESXi 6, vCenter
Server 6). The VMs are running Windows 7 SP1.

I am able to establish successful connections to certain machines and not
others.  The connection settings are identical.

The connections are part of a connection group which has 12 individual
connections.  Any recommendations would be greatly appreciated.  Thank you.

Log output to /var/log/tomcat/catalina.out:
This is what I think is the most relevant utput for my failed RDP
connections. But I can provide more if necessary.
15:28:22.750 [http-nio-8080-exec-9] DEBUG
o.g.g.w.GuacamoleWebSocketTunnelEndpoint - Connection to guacd closed.
org.glyptodon.guacamole.GuacamoleConnectionClosedException: Connection to
guacd is closed.
    at
org.glyptodon.guacamole.io.WriterGuacamoleWriter.write(WriterGuacamoleWriter.java:69)
~[guacamole-common-0.9.9.jar:na]
    at
org.glyptodon.guacamole.io.WriterGuacamoleWriter.write(WriterGuacamoleWriter.java:78)
~[guacamole-common-0.9.9.jar:na]
    at
org.glyptodon.guacamole.websocket.GuacamoleWebSocketTunnelEndpoint.onMessage(GuacamoleWebSocketTunnelEndpoint.java:218)
~[guacamole-common-0.9.9.jar:na]
    at
org.glyptodon.guacamole.websocket.GuacamoleWebSocketTunnelEndpoint$1.onMessage(GuacamoleWebSocketTunnelEndpoint.java:133)
[guacamole-common-0.9.9.jar:na]
    at
org.glyptodon.guacamole.websocket.GuacamoleWebSocketTunnelEndpoint$1.onMessage(GuacamoleWebSocketTunnelEndpoint.java:129)
[guacamole-common-0.9.9.jar:na]
    at
org.apache.tomcat.websocket.WsFrameBase.sendMessageText(WsFrameBase.java:393)
[tomcat-websocket.jar:8.0.28]
    at
org.apache.tomcat.websocket.WsFrameBase.processDataText(WsFrameBase.java:494)
[tomcat-websocket.jar:8.0.28]
    at
org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:289)
[tomcat-websocket.jar:8.0.28]
    at
org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:130)
[tomcat-websocket.jar:8.0.28]
    at
org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:60)
[tomcat-websocket.jar:8.0.28]
    at
org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onDataAvailable(WsHttpUpgradeHandler.java:203)
[tomcat-websocket.jar:8.0.28]
    at
org.apache.coyote.http11.upgrade.AbstractServletInputStream.onDataAvailable(AbstractServletInputStream.java:198)
[tomcat-coyote.jar:8.0.28]
    at
org.apache.coyote.http11.upgrade.AbstractProcessor.upgradeDispatch(AbstractProcessor.java:96)
[tomcat-coyote.jar:8.0.28]
    at
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
[tomcat-coyote.jar:8.0.28]
    at
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
[tomcat-coyote.jar:8.0.28]
    at
org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
[tomcat-coyote.jar:8.0.28]
    at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
[na:1.8.0_71]
    at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
[na:1.8.0_71]
    at
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
[tomcat-util.jar:8.0.28]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_71]
Caused by: java.net.SocketException: Socket closed
    at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:116)
~[na:1.8.0_71]
    at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
~[na:1.8.0_71]
    at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221)
~[na:1.8.0_71]
    at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291)
~[na:1.8.0_71]
    at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:295)
~[na:1.8.0_71]
    at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141) ~[na:1.8.0_71]
    at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229)
~[na:1.8.0_71]
    at
org.glyptodon.guacamole.io.WriterGuacamoleWriter.write(WriterGuacamoleWriter.java:63)
~[guacamole-common-0.9.9.jar:na]
    ... 19 common frames omitted



Best
Miguel