Unable to negotiate with ssh

[Kerogaz]

ssh n@n.n.n.n
Unable to negotiate with n.n.n.n port 22: no matching host key type found. Their offer: ssh-rsa, ssh-dss
I have to delete his entry from here
sudo nano /home/manro/.ssh/known_hosts
And then
ssh -oHostKeyAlgorithms = + ssh-dss n@n.n.n.n
After that, you can connect, but if you leave the session, then you need to do everything in a new way

[linux-aarhus]

You can setup an entry for the host in your .ssh/config this will save you the trouble of adding it.

The change has something to do with ciphers now considered unsafe - and the issue is with servers running older versions of openssh.

[freggel.doe]

Also the the known (older) issues of latest announcement:

[Stable Update] 2021-10-16 - Haskell, Python, KDE Gear, KDE Framework, Thunderbird

Known issues and solutions This is a wiki post; please edit as necessary. Please, consider subscribing to the Stable Updates Announcements RSS feed Please don’t post to say everything was great on my side or yes, I have the same error but leave the space for people having issues, or even better: for people having solutions! Use instead to let us know you’re suffering from the same so we can respond to the highest impacted issues first! …

If you want to keep using rsa keys and/or cannot change host keys:

Latest update ssh stopped supporting RSA?

I had this issue with bitbucket the other day, as a work around I put this in my ~/.ssh/config Host bitbucket.org HostkeyAlgorithms +ssh-rsa PubkeyAcceptedAlgorithms +ssh-rsa Basically it’s been disabled in open ssh for security reasons and bitbucket hasn’t updated their servers yet (don’t know what you’re connecting to)

[Kerogaz]

But why if I put on my computer a hard drive with installed mint or mx linux, the connection with the same server via ssh is established without problems ? I connect to my remote server with operating system CentOS 6. This is the control server of the compute cluster

[freggel.doe]

@Kerogaz

mint or mx linux

Because those 2 use an older openssh version to connect to the server…
Also see https://www.openssh.com/txt/release-8.8

[Kerogaz]

Thanks