This error occurs because some older key algorithms are no longer supported by newer servers in that it’s considered insure. ==If possible, upgrade the client instead of using the method below.==

A way to force the server(openssh at here) to use it:

1.Adding KexAlgorithms diffie-hellman-group1-sha1 to /etc/ssh/sshd_config. For example:

sudo echo “KexAlgorithms diffie-hellman-group1-sha1” >> /etc/ssh/sshd_config

2.Restart the ssh server:

sudo service ssh restart

2017/2/27