16.04: No ECDSA host key is known for XXXXX and you have requested strict checking.

[Tom H]

On Sun, Jul 24, 2016 at 5:21 AM, Josef Wolf <jw at raven.inka.de> wrote:
>
> when connecting from machines with older ssh releases, I get the error
> mentioned in the subject.
>
> I have abondoned DSA keys because they can easily be compromized. ECDSA is
> told to have similar weaknesses as DSA.
>
> I undersand that ec25519 is noo new for older clients. But why won't they fall
> back to the RSA key that is also available?

DOn't you need both keys in know_hosts for a fallback?

Get the public keys with "ssh-keyscan old-server-ip-address" and add
the one that you want to use to "~/.ssh/known_hosts"