RUT955 SSH connection

I have several RUT955 routers connected to remote security systems. They are Solar and Wind powered so I wire the battery to the analogue input and i run a PHP script which sends an SSH command to get the Voltage of the battery every hour, updates a DB table which i can use to display on a live monitoring board.

I updated a couple of routers to latest firmware and now get an error saying,

Error starting up SSH connection(-8): Unable to exchange encryption keys.

This only happens on the new firmware, and only from the PHP script which is using ssh2. I am still able to connect via putty from my windows pc, and from the terminal of my web server where the PHP script runs.

This error is happening at the Handshake stage, before even attempting any authorization either by Password or Key pair. Both of these methods work perfectly fine through Putty.

Just to throw another curve ball, i have 2 rut955 with the latest firmware on RUT9_R_00.07.04.4 and they work fine with the exact same setup.

Any help appreciated.



While I cannot help with your code, I believe that this can be related to the following change in the newer firmware:


Check your code and ensure that it works with ECDSA and ED25519 keys.

Kind Regards,

Thank you for your reply. But this is not the reason. I have several routers with the 7.04.3 firmware on and they all work absolutley fine. The problem is only with the next version 7.04.4. I have downgraded one of the problem routers to 7.04.3 and it now works.


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