Debugging SSH connections

SSH is a very useful tool for accessing a remote system using a console (terminal).  There are also very many options and sometimes debugging a problematic SSH connection over remote.it can be challenging. 

Search for the error message

If you've received a specific error message, try searching for it using the search bar at the top of this page.  You can also see common SSH error message, causes and solutions here.

Check the connection address in your browser

Address from the Remote.It web portal

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Copy the local address using the leftmost icon as shown, then paste it into your browser's address bar.  Preface the address with "http://" as shown, then hit enter.

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If everything is working, you should see the SSH server banner:

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When using an SSH connection in your browser, the "Protocol mismatch" message is expected.  Any other response, or no response is an indication that either you have not connected to the SSH server or something else is wrong.

Address from the Remote.It Desktop application with "Named Connections" enabled

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Copy the local address using the leftmost icon as shown, then paste it into your browser's address bar.  Preface the address with "http://" as shown, then hit enter.

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If everything is working, you should see the SSH server banner:

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When using an SSH connection in your browser, the "Invalid SSH identification string." message is expected.  Any other response, or no response is an indication that either you have not connected to the SSH server or something else is wrong.

Address from the Remote.It Desktop application with "Named Connections" disabled

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Copy the local address using the leftmost icon as shown, then paste it into your browser's address bar.  Preface the address with "http://" as shown, then hit enter.

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If everything is working, you should see the SSH server banner:

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When using an SSH connection in your browser, the "Invalid SSH identification string." message is expected.  Any other response, or no response is an indication that either you have not connected to the SSH server or something else is wrong.

Search for all articles which mention SSH on this site
Click on this link to find all articles which mention SSH in our Knowledge Base.
Use the verbose mode of the SSH command
ssh -v -v username@hostname -p port

 (use the -v -v option on the SSH command line)

If you need to contact support

Here's a list of things we'll probably want to know when you have trouble using SSH with remote.it.

This info lets us look up a specific connection attempt:

  • Your remote.it account user name
  • Device name
  • Time of connection
  • connection details (e.g. proxy14.rt3.io, port 34016)
  • Were you using the web portal, mobile, or Desktop application

This info will help us understand what type of system you are using and what programs (TCP listeners)  are detected:

uname -a

(what type of device/OS is this)

sudo netstat -lpn | grep tcp

(show active TCP listeners)

This info is general background around the ssh client and server

  • Information of initiator (OS, SSH client software)
  • Information of target (OS, SSH server software/version)

Running these commands on the target tells us about the installation

/usr/share/remoteit/connectd -n

 (run a network test on the device)

ps ax | grep connectd |grep -v grep

(which connectd daemons are running)

Other tests to run on the target, if you can connect directly or using VNC

  • ssh -v username@localhost (see if SSH server accepts a connection from localhost - required to use connectd, but this test can be run without connectd)

Other information:

  • Behavior details of issue
  • Whether this issue happens all the time or intermittently

What to try if all else fails

  • Try rebooting the router.  Sometimes routers can run out of memory which may make Remote.It behave unpredictably.  Test this by running the command below on the target device or any other Remote.It enabled device on the same LAN.   Contact tech support with the results.
/usr/share/remoteit/connectd -nat
  • Review syslog data on target device (e.g. Raspberry Pi: /var/log/messages, Ubuntu: /var/log/syslog)
  • Collect packet trace data (initiator side, target side) if possible.
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