OpenSHH stops listening after first connect

  • Hi all,

    I have to provide SFTP via OpenSSH on Windows Server 2003 for UNIX AIX
    machines. I installed version 3.8.1 of OpenSSH, learned the configuration and
    was happy to connect successfully via WinSCP with username and password. But
    it works only once after starting the OpenSSH service. The second attempt with
    WinSCP returns a "connection refused". When I restart the OpenSSH service, I
    can connect the machines and can do SFTP. As soon as this connection is closed
    I have to restart the service again (etc.). By using the VERBOSE flag in
    sshd_config, my current assumption is OpenSSH stops listening on Port 22 after
    closing the connection because no new protocol entry is written after.

    Any help is appreciated!

    Thank you

  • one addition: when I connect with PuTTY on local, I get the same result. 1st
    attempt is ok, 2nd attempt network error.

  • next addition:

    after closing the session with WinSCP the OpenSSH service on windows stops.

    here are the latest log entries:

    Accepted password for Administrator from port 2778 ssh2

    debug1: Entering interactive session for SSH2.

    debug2: fd 3 setting O_NONBLOCK

    debug2: fd 7 setting O_NONBLOCK

    debug1: server_init_dispatch_20

    debug1: server_input_channel_open: ctype session rchan 256 win 2147483647 max

    debug1: input_session_request

    debug1: channel 0: new

    debug1: session_new: init

    debug1: session_new: session 0

    debug1: session_open: channel 0

    debug1: session_open: session 0: link with channel 0

    debug1: server_input_channel_open: confirm session

    debug1: server_input_channel_req: channel 0 request reply 0

    debug1: session_by_channel: session 0 channel 0

    debug1: session_input_channel_req: session 0 req

    debug1: server_input_channel_req: channel 0 request subsystem reply 1

    debug1: session_by_channel: session 0 channel 0

    debug1: session_input_channel_req: session 0 req subsystem

    subsystem request for sftp

    debug1: subsystem: exec() /usr/sbin/sftp-server

    debug2: fd 10 setting O_NONBLOCK

    debug2: fd 9 setting O_NONBLOCK

    debug2: channel 0: rcvd eof

    debug2: channel 0: output open -> drain

    debug2: channel 0: obuf empty

    debug2: channel 0: close_write

    debug2: channel 0: output drain -> closed

    Connection closed by

    debug1: channel 0: free: server-session, nchannels 1

    debug1: session_close: session 0 pid 3664

    debug1: do_cleanup

    Closing connection to <... my ip address ...>