sudo adduser luca
sudo usermod -aG sudo luca
sudo adduser luca
sudo usermod -aG sudo luca
client> sudo adduser luca # your user
client> sudo usermod -aG sudo luca
client> ssh-keygen -t rsa -b 4096 -C "luca@ubuntu-srv-1"
client> ssh-keygen -t rsa -b 4096 -C "luca@ubuntu-srv-2"
client> nano .ssh/config
# paste in the following
Host 1srv
HostName 192.168.23.199 # your ip
User luca
IdentityFile ~/.ssh/id_rsa_luca_ubuntu-srv-1
Host 2srv
HostName 192.168.23.197 # your ip
User luca
IdentityFile ~/.ssh/id_rsa_luca_ubuntu-srv-2
client> ssh 1srv
1srv> mkdir .ssh
1srv> nano .ssh/authorized_keys
# paste in the public key from luca@ubuntu-srv-1
1srv> exit
client> ssh 2srv
2srv> mkdir .ssh
2srv> nano .ssh/authorized_keys
# paste in the public key from luca@ubuntu-srv-2