mRemoteNG – Couldn’t agree a host key algorithm (available rsa-sha2-256)

by

I was having the issue in mRemoteNG where some hosts were showing the error: “Couldn’t agree a host key algorithm (available rsa-sha2-256)” when attempting to SSH to them.

And even when ensuring all the ciphers are enabled with the Default Settings (session) -> Connection -> SSH -> Cipher, the issue was still observed.

Turns out the mRemoteNG uses its own version of Putty, called PuttyNG.exe in my case I was using an older version, hence the issue appearing, no amount of upgrading my normal Putty or updating the configurations would help.

Resolution

  1. Download the new version of PuTTYNG (version 0.83 at the time of writing) from https://github.com/mRemoteNG/PuTTYNG/releases
  2. Take a backup of the existing version, e.g. rename to PuTTYNG-old.exe for example.
  3. Place PuTTYNG.exe into mRemoteNG directory overwriting the existing version my directory was: c:\Program Files (x86)\mRemoteNG yours may differ.

You should now be able to log into these hosts via SSH without an issue.

Leave a comment