SSH login slowness troubleshooting

In newly installed servers, while trying to login using  "ssh" we may feel some slowness to get the password prompt . Most of us think that this is due to network level DNS issue, but actually the assumption is wrong there is a  parameters in the SSH configuration file which makes delay in getting this password prompt.

          Let us see the solution for the above issue in Sun SSH and Open SSH.

In SunSSH, 

Add the mentioned parameter in the file /etc/ssh/sshd_config

LookupClientHostnames no

In OpenSSH,

Edit the mentioned parameter in the file /etc/ssh/sshd_config

UseDNS no
              After that restart the ssh service and check the response of quick password prompt while login to the servers through ssh