If you want to give access to your domain only for a single IP address. In such case, create an htaccess file(.htaccess) and add the content given below.
Order Deny,Allow
Deny from all
Allow from <ip address>
Note: replace the <ip address> with the original IP address.
Order Deny,Allow
Deny from all
Allow from <ip address>
Note: replace the <ip address> with the original IP address.