Go to the switch log in, go to security, access then SSH. You can see here no keys are present. Use SSH2 as it’s more secure, so go over to the host keys management page, generate the DSA and RSA keys, then apply – wait for a little, now you can enable SSH admin, (disable version1) 

info on v1 vs v2 and in general

From a terminal you can now log in – but you may get an error in which case use a specific key exchange as pictured. 

ssh -oKexAlgorithms=+diffie-hellman-group14-sha1 admin@0.0.0.0

Once in, use the ? to see the commands available, and enable then ? for the administration commands. 

if you need to remove the ssh key with ‘ssh-keygen -R “hostname”‘

you can add the key algorthym perminantly to your ssh hosts file

add Host 123.123.123.123 KexAlgorithms +diffie-hellman-group14-sha1
to ~/.ssh/config.