SSH client configuration

These are the options:

• /etc/ssh/ssh_config
• ~/.ssh/config
• -o

Permissions of SSH config file should be 600 or 400: Before editing use:

$ OLDUMASK=$(umask)
$ umask 0077

Next, edit SSH config file. After editing - restore umask:

$ umask $OLDUMASK

Sample contents of ~/.ssh/config or /etc/ssh/ssh_config:

Host *
  ServerAliveInterval 300
  ServerAliveCountMax 2
Host ubuntu2
  Hostname 192.168.56.102
  User tux
  IdentityFile ~/.ssh/id_rsa

-o command line option examples:

ssh -o ServerAliveInterval=300 -o ServerAliveCountMax=2 tux@192.168.56.102
ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no  tux@192.168.56.102