In case you are hosting your sites in Plesk and have an independent DNS server that acts as a main server (Master), you have the possibility to have Plesk act as a secondary server (Slave). In order to switch the two servers, follow the instructions described below:

1. Log into myTophost Panel and click on Plesk Login in order to connect to the Plesk of the plan that you are interested in.

2. In the Websites & Domains tab, click on DNS Settings.

In order for Plesk to become your main server:

1. Click on Master/Slave.

NOTE: Plesk will confirm that it has become the primary server (Master).

See also: How can I change my DNS service from Master to Slave through Plesk?