Anyone using this feature and could explain their setup to me?

Lets set up a situation:

I have server plesk1 with ip 127.0.0.1 and I have plesk2 with ip 127.0.0.2

I register plesk1.blah.com and plesk2.blah.com as my name servers.

Now I want plesk1 to be the master server and handle all zones and dns requests and I want plesk2 to handle it for backup. How would I go about setting this up in plesk using it's acl feature......