On 24.02.2017 01:14 AM, jmmec2014@yahoo.com wrote:
> I don't know why Windows 8.1 was suddenly only supporting ssh-ed25519 and
> failing to connect to my Linux Mint session with that "kex error".  What is even
> stranger:  the problem suddenly went away and I could once again use the x2go
> client to connect to that session (the same session that I've had running for
> more than a month - maybe two months by now).  At least for now the "kex error"
> is gone with the X2GO client.

Stefan just had the same problem. Then it struck me - he's using DHCP in his
network and IP addresses of virtual machines often get reassigned addresses
based on which ones are free (hence the addresses are only pseudo-static.)

He tried to connect to a CentOS 5 box and got the same error. The problem was
that this exact host was already recorded in his known_hosts file with an ED key
- this is why libssh advertised only knowing ED-type keys. After moving the
known_hosts file out of the way, the connection was established okay.

In general a little bit less weird, though, as in his output the server
advertised both RSA and DSA keys, like you'd expect of a CentOS 5 machine.


A similar thing probably happened to you.