Dear Group Members,

I have a problem with parallel remote kernels over SSH in Mathematica 7.0.
The host is running WinXP Pro, SP3, Mathematica 7.0.1, openssh client+server
are installed.
The remote machine is running Ubuntu 9.10, Mathematica 7.0.1, openssh
client+server installed

*** WHAT WORKS:
I can assign  single remote machine kernels using Evaluation -> Kernel
Configuration Options with
Arguments to MLOpen:
-LinkMode Listen -LinkProtocol TCPIP -LinkOptions MLDontInteract

Shell command to launch Kernel:
"`java`" -jar "`mathssh`" pet@hostname math -mathlink -LinkMode Connect
-LinkProtocol TCPIP -LinkName "`linkname`" -LinkHost `ipaddress`

This works fine and I can compute my notebook with that remote kernel.



*** WHAT DOES NOT WORK (even not when firewall is turned off):

I am NOT able to launch the remote kernels on the Ubuntu machine from the
WinXP machine in parallel via Evaluation -> Parallel Kernel Configuration ->
Remote Kernels. I add my host liks this:
Hostname: hostname
Use custom launch command:
ssh -x -f pet@hostname math -mathlink -linkmode Connect =B44=B4 -linkname '=B42=B4'
-noinit

Executing ssh pet@hostname math in a command window runs and displays the
remote machine's kernel ln[] where I can compute as usual. So ssh should not
be the problem.
The error message is:  LinkConnect::linkc: -- Message text not found --
(LinkObject[4119@141.39.169.106,4120@141.39.169.106, 1, 1])

where 141.39.169.106 is the IP address of the WinXP host.


*** Other tries that DID NOT WORK:
to tunnel via ssh:
C:\Programme\OpenSSH\bin\ssh.exe -R 31415:127.0.0.1:31415 -R
31416:127.0.0.1:31416 pet@141.39.169.47 "math -mathlink -LinkMode Connect
-LinkProtocol TCPIP -LinkName 31415@127.0.0.1,31416@127.0.0.1 -LinkHost
127.0.0.1"

or the use of plink.exe
C:\plink.exe -batch -v -ssh -C -x -l "pet" -pw "iluzionist" 10.0.0.2
"/usr/local/bin/math" -mathlink -LinkMode Connect -
LinkProtocol TCPIP -LinkName `linkname`



*** Note that the other direction (From Ubuntu to Windows via ssh, analog
custom launch command as mentioned above) I am able to launch the additional
Kernels of the Windows machine, they appear in the Parallel Kernels Window.


Please, can someone help? Any suggestions?

Cheers!
Jozef

Hello Jozef & Group members,

I know I am digging up a 3 year old thread but since I have the same problem (although remote kernel working on OS X 10.8 client via ssh in openVPN to Debian remote server, but not on WIndows 7 client, where I used the latest implementation of openssh in cygwin) I wondered if you or someone had solved that problem in the meantime.

If you read this and found the solution, would you please be so kind and post it here so others could be helped? I asked my problem already on stackexchange: http://mathematica.stackexchange.com/questions/21231/remote-mathkernel-ssh-encountered-a-networking-error-while-launching-kernel-err but haven't got a solution so far..I am linking your question also there in hopes someone might be able to help.

thanks in advance,
hajn 

 ssh -x -f pet@hostname math -mathlink -linkmode Connect =B44=B4 -
linkname '=B42=B4'
-noinit

what is =B44?  why not use hostname?  if you can't use "hostname" toss
the thing.

ssh does (let's say in most or all versions) change data in the stream
and interferes with X windows - which is an issue never resolved as
far as I know.  however let's assume that's not the issue...

You have not said if the above works when "ssh" is not in use.

If you need "privacy" why not try connection level privacy, ie,
ipsecure or vpn, instead of a program (ssh) which hacks inside the
connection stream (obviously on a per-connection basis)?

i never understood why ssh hacked inside the stream instead of
wrapping it.  it's mind bending.