Disable DNS lookup for SSH service

Sometimes the SSH service tries to resolve an unknown IP address which would cause a delay in the login process. This can be disabled to avoid DNS look and quicken the login time.

Step-by-step guide

Edit the file '/etc/ssh/sshd_config'

vi /etc/ssh/sshd_config

Add a new line at the end with the following:

UseDNS no

Restart the SSH service

service ssh restart