Multiple connections to the same server fails

I'm trying to connect multiple times to the same server, but the sessions stalls/freezes. It only becomes active when I close the first connection to the same server. This must be something wrong on the application as I can ssh to the same servers multiple times without any issues.

How may sessions did you made? I made five sessions to the same remote host, all sessions keep active.

Is this issue always reproducible? May I ask the a more detailed reproduce steps?


I tried connecting multiple times (more than one) to six different servers, all showed the same app behavior. I do not have the issue with SecureCRT or plain old ssh from the cli.

Its always reproducible. I attached an animated gif.

I connect to any server, then open new tab to same server.

2021-08-12 12.52.23

Kennie, thank you so much for the animated gif

Could you please also set debug level to DEBUG3 and pasted desensitized log, this will help me identify the problem.


Attached working session and stalled session logs.

working-session.txt (13 KB)

stalled-session.txt (1.54 KB)

It seems you have enabled ControlMaster and/ or ControlPath, please check your ~/.ssh/config line 22 and /etc/ssh/ssh_config line 47, comment multiplexing relate directives should fixed the problem.

BTW, could you please also post your multiplexing configuration? The multiplexing is tricky, perhaps Core Shell doesn't handle some use cases.


Yes, I need this enabled for ansible. Also, this does not affect the regular ssh cli. I have the same configuration on my work Mac and it does not affect SecureCRT or the ssh cli either.

Host *
ControlMaster auto
ControlPath ~/.ssh/multiplex/%r@%h:%p
ControlPersist 1
User cruzkj
ServerAliveInterval 120
VisualHostKey yes
  • Kennie Cruz

Thank you very much for the information, will fix it in next update.

Kindly Regards,


Thank you.

  • Kennie Cruz

Hi Kennie, we just released Core Shell 3.5 Beta, and invited you join our Beta Program.

This issue was caused by defective ssh multiplexing support. Core Tunnel 3.5 beta now gains full support for multiplexing directives (i.e. ControlPath and ControlMaster).

Please let me know if you find any bugs on this feature.

Thanks you very much for reporting the issue.


Wow! It works! I will keep testing the app. Thank you very much.

  • Kennie Cruz
1 Like