[CentOS] Delay in SSH login..

[Jim Perrin]

> =========================================
>  Can you please advice what is the correct way to disable it.

Sure. A brief reading from TFM:

UseDNS: Specifies whether sshd should lookup the remote host name and
check that the resolved host name for the remote IP address maps back
to the very same IP address.  The default is "yes".

If you're going to disable DNS lookups, set this to 'NO'.

--
Any sufficiently advanced technology is indistinguishable from magic.
-Arthur C. Clarke