I'm trying to use scp for copying files from SuSE 9.1 (running under
VMware Workstation on Windows) to a remote host, also running SuSE 9.1.
Both installations are at 4.1p1-11.16 (the remote host started out at
3.8p1-37.17, with the same problems).

To avoid ssh disconnects due to inactivity, I set

ClientAliveInterval 60

in sshd_config; everything else is default. At this point I'm going from
root to root, using public key authorization.

ssh works just fine, both from the command line as well as via Midnight
Commander's shell link. Either way I can copy files from remote to
local, but when I try to copy from local to remote, then scp and mc's
fish usually hang and time out after a few minutes. Every now and then a
small file may go through, but usually not.

BTW, with Putty PSCP on the local Windows computer everything works just
fine both ways.

I've spent all day today to try to find a solution, and now I'm becoming
desperate... Here are the outputs from scp -vvv and from sshd
(LogLevel DEBUG3), first last part of the scp log of successfully
sending a short 32-bit file:

debug1: Sending command: scp -v -t 32-byte-file
debug2: channel 0: request exec confirm 0
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel 0: rcvd adjust 131072
Sending file modes: C0755 32 32-byte-file
debug2: channel 0: rcvd ext data 23
Sink: C0755 32 32-byte-file
debug2: channel 0: written 23 to efd 11
debug2: channel 0: read<=0 rfd 8 len 0
debug2: channel 0: read failed
debug2: channel 0: close_read
debug2: channel 0: input open -> drain
debug2: channel 0: ibuf empty
debug2: channel 0: send eof
debug2: channel 0: input drain -> closed
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
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
debug2: channel 0: rcvd close
debug3: channel 0: will not send data after close
debug2: channel 0: almost dead
debug2: channel 0: gc: notify user
debug2: channel 0: gc: user detached
debug2: channel 0: send close
debug2: channel 0: is dead
debug2: channel 0: garbage collecting
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
#0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cfd -1)
debug3: channel 0: close_fds r -1 w -1 e 11 c -1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
debug1: fd 2 clearing O_NONBLOCK
debug1: Transferred: stdin 0, stdout 0, stderr 0 bytes in 0.6 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0
debug1: Exit status 0


Here's the failed attempt to send a ~20K-byte file:

debug1: Sending command: scp -v -t 20K-byte-file
debug2: channel 0: request exec confirm 0
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel 0: rcvd adjust 131072
Sending file modes: C0644 22479 20K-byte-file
debug2: channel 0: rcvd ext data 28
Sink: C0644 22479 20K-byte-file
debug2: channel 0: written 28 to efd 11
debug1: client_input_channel_req: channel 0 rtype keepalive@openssh.com
reply 1
debug1: client_input_channel_req: channel 0 rtype keepalive@openssh.com
reply 1
debug1: client_input_channel_req: channel 0 rtype keepalive@openssh.com
reply 1
Received disconnect from <>: 2: Timeout, your session not
responding.
lost connection

The three client_input_channel_req lines correspond to the
ClientActiveInterval 60 setting, coming in at 1 minute intervals.


From the sshd side, there's a similar picture: the initial setup is the
same, and here's where it starts to differ -- first the successful
transfer with the tiny file:

20:50:16: debug2: channel 0: read 23 from efd 9
20:50:16: debug2: channel 0: rwin 131070 elen 23 euse 1
20:50:16: debug2: channel 0: sent ext data 23
20:50:16: debug2: channel 0: rcvd eof
20:50:16: debug2: channel 0: output open -> drain
20:50:16: debug2: channel 0: obuf empty
20:50:16: debug2: channel 0: close_write
20:50:16: debug2: channel 0: output drain -> closed
20:50:16: debug1: Received SIGCHLD.
20:50:16: debug1: session_by_pid: pid 14381
20:50:16: debug1: session_exit_message: session 0 channel 0 pid 14381
20:50:16: debug2: channel 0: request exit-status confirm 0
20:50:16: debug1: session_exit_message: release channel 0
20:50:16: debug1: session_close: session 0 pid 14381
20:50:16: debug2: channel 0: read<=0 rfd 7 len 0
20:50:16: debug2: channel 0: read failed
20:50:16: debug2: channel 0: close_read
20:50:16: debug2: channel 0: input open -> drain
20:50:16: debug2: channel 0: read 0 from efd 9
20:50:16: debug2: channel 0: closing read-efd 9
20:50:16: debug2: channel 0: ibuf empty
20:50:16: debug2: channel 0: send eof
20:50:16: debug2: channel 0: input drain -> closed
20:50:16: debug2: channel 0: send close
20:50:16: debug2: notify_done: reading
20:50:16: debug3: channel 0: will not send data after close
20:50:16: debug2: channel 0: rcvd close
20:50:16: debug3: channel 0: will not send data after close
20:50:16: debug2: channel 0: is dead
20:50:16: debug2: channel 0: garbage collecting
20:50:16: debug1: channel 0: free: server-session, nchannels 1
20:50:16: debug3: channel 0: status: The following connections are
open:\r\n #0 server-session (t4 r0 i3/0 o3/0 fd 7/7 cfd -1)\r\n
20:50:16: debug3: channel 0: close_fds r 7 w 7 e -1 c -1
20:50:16: Connection closed by 83.78.50.109
20:50:16: debug1: do_cleanup
20:50:16: debug1: PAM: cleanup
20:50:16: debug3: PAM: sshpam_thread_cleanup entering
20:50:16: Closing connection to 83.78.50.109
20:50:16: debug1: PAM: cleanup


.... then the failed transfer:

20:54:11: debug2: channel 0: read 28 from efd 9
20:54:11: debug2: channel 0: rwin 131071 elen 28 euse 1
20:54:11: debug2: channel 0: sent ext data 28
20:55:11: debug2: channel 0: request keepalive@openssh.com confirm 1
20:56:11: debug2: channel 0: request keepalive@openssh.com confirm 1
20:57:11: debug2: channel 0: request keepalive@openssh.com confirm 1
20:58:11: Disconnecting: Timeout, your session not responding.
20:58:11: debug3: channel 0: close_fds r 7 w 7 e 9 c -1
20:58:11: debug1: do_cleanup
20:58:11: debug1: PAM: cleanup
20:58:11: debug3: PAM: sshpam_thread_cleanup entering

After the first three lines it just stops, without any error message,
then the three keep-alive exchanges in one minute intervals, and then
the timeout.

Please help!

Hans