Strange crypto choices

[Stuart Henderson]

Answering the first part of your mail:

On 2018-05-25, Yegor Ievlev <koops1997 at gmail.com> wrote:
> The defaults for HostKeyAlgorithms option are:
>
> ecdsa-sha2-nistp256-cert-v01 at openssh.com,
> ecdsa-sha2-nistp384-cert-v01 at openssh.com,
> ecdsa-sha2-nistp521-cert-v01 at openssh.com,
> ssh-ed25519-cert-v01 at openssh.com,
> ssh-rsa-cert-v01 at openssh.com,
> ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
> ssh-ed25519,ssh-rsa
>
> Why does OpenSSH prefer older and less secure
> (https://safecurves.cr.yp.to/) ECDSA with NIST curves over Ed25519?

Changing HostKeyAlgorithms means that the existing entries in known_hosts
don't match, so the "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED"
message is triggered.