SSH-Connection: Transfer from ssh/root to local failed: channel is not opened.

I am trying to connect from ssh to an sftp server. The ssh connection node seems to work fine, but the download node returns the message described in the topic.

WARN Download 0:200 Transfer from ssh://—@-------/MIS2019.xls to file:/C:/Users/rgutierrezr/Desktop/MIS2019.xls failed: channel is not opened.

I don’t understand why this problem occurs, if I try to download from an sftp client I can do it without problems …

Hi @rwa_gr,

I think the connection node will not throw an error. (even if the connection is not working)
Could you confirm that you get the same error when using list files node on the connection?

Could you increase the timeout on the connection node? (e.g. to 60.000 or 120.000)

Are you behind a company proxy which might interfere with the ssh connection? (e.g. does it help to change the knime proxy settings to direct)

Which KNIME Version are you using? 4.3?:thinking:

Thanks for reply.

If I change the node to List remote files the same problem happens even if I increase the timeout.

I am not an expert in proxy connections but I use a VPN to access the company remotely. However, I think that if something could be interfering with the connection then it should not be accessed from an sftp client which I only configure the user and host credentials.

I’m using Knime version 4.1

Hi @rwa_gr,

VPN should not be an issue.
(at least if you can do it manually with an ssh client while connected)

But if the increased timeout does not work then i can only guess how to fix the problem :see_no_evil:

I think you can google for jsch and your error for detailed explenations on the error message (should be the java library behind the node)
But in general I think the connection does not go through to the server)

can you do the following in the cmd/console on your machine (if you are using Windows)

sftp username@sshHostname


can you connect there?
In case it asked if you want to add the host to the known hosts - answer Y and try the SSH nofr again.



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:see_no_evil: actually hoped this would fail - so the issue would become clearer :frowning:

But at least the connection and login should not be the problem :thinking:
Maybe the last thing I can think of is trying a newer knime version (there is a new SSH node in 4.3)
e.g. just download the zip version of 4.3 and try if it works with the updated SSH node

In general I used the 4.1 version quite alot - and it should work :frowning:

Maybe someone else has any idea what else could be the problem :see_no_evil:

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