Debugging ssh permission denied for password-less login

Sometimes after setting up password less login using ssh, you still get the password prompt when a login is attempted. The reason could be multifold. This is how you can go about debugging the problem.

• use the -v switch with ssh. This will give you the detailed steps of all that ssh tried before falling back to the password prompt.
• Login to the machine where you were trying to connect to and look at the auth logs on the machine. (Note: Auth logs are located @/var/log/auth.log. )
• Often the problem is that you have to add the users group to "AllowGroups" property in /etc/ssh/sshd_config file.