Failed to connect any ssh host

env: ubuntu

ref: https://blog.csdn.net/C_W_0/article/details/122953132

• Please check first if you have installed openssh.
• And try restarting sshd service:

sudo service ssh restart
sudo service sshd restart
sudo /etc/init.d/ssh restart

this worked, on 24/5/28, for a new user on Ubuntu.