LinuxQuestions.org - "Shared connection to host closed."

Hello. This is not my first post, but I don't remember the username I used to use and apparently used an old email address. So, it's a new account for me.

I have a need to remotely administrate a Windows 7 machine. (I know. It's LinuxQuestions.org, not WindowsQuestions.org... but bear with me... please?) Having much more experience with Linux than Windows and knowing the amount of power Linux utilities would give me for administrating the box, I installed Cygwin and OpenSSH.

Given the bandwidth and latency considerations, I'll be using a ControlMaster ssh connection and running various ssh-related commands (such as bash, port forwarding, scp, etc) through that.

I've got it all set up, and it all works except for one thing.

I set up the master connection with:

Code:

ssh -fCNMS /tmp/ssh.sock user@host

I can run a remote shell with:

Code:

ssh -S /tmp/ssh.sock user@host

However, if I end the remote shell (with ctrl-d or "exit") and try to run it through the same master connection again, I get the following:

Code:

> ssh -vvv -s /tmp/ssh.sock user@host

openssh_5.9p1-hpn13v11, openssl 1.0.0j 10 may 2012

debug1: reading configuration data /home/localuser/.ssh/config

debug1: reading configuration data /etc/ssh/ssh_config

debug2: fd 3 setting o_nonblock

debug2: mux_client_hello_exchange: master version 4

debug3: mux_client_request_forwards: requesting forwardings: 0 local, 0 remote

debug3: mux_client_request_session: entering

debug3: mux_client_request_alive: entering

debug3: mux_client_request_alive: done pid = 6976

debug3: mux_client_request_session: session request sent

warning: untrusted x11 forwarding setup failed: xauth key data not generated

warning: no xauth data; using fake authentication data for x11 forwarding.

debug1: mux_client_request_session: master session id: 2

x11 forwarding request failed

last login: sat dec 15 23:07:49 2012 from 192.168.1.101

debug3: mux_client_read_packet: read header failed: broken pipe

debug2: received exit status from master 255

shared connection to host closed.

Also, I can copy files to the remote machine with:

Code:

scp -o ControlMaster=no -o ControlPath=/tmp/ssh.sock file.txt user@host:/tmp

However, doing that a second time fails with the message "lost connection".

Closing the master connection and restarting the connection lets me open a shell or scp a file again.

I'm not sure whether it's a client or server issue, but even though the server is on Cygwin, I imagine you folks will have an idea what's up.

Thanks in advance for your help!