ZoneEdit as Slave DNS?

I have one Master DNS. For example:

How to setup and as Slaves?

The result is: (Primary) (Slave) (Slave)

Chris Cherry

Mr. Happy To Help You.
You can configure us to Slave off your Primary NS by managing your domain name and clicking the "DNS Settings" tab.

Look for the "primary NS" link on the Secondary Information line.

You'll be required to add the IP of the nameserver we're slaving off and then enter our IP's into the ACL for your nameserver as shown on the Edit Primary Name Servers page.

Make sure your primary zone's serial number is higher than ours for it to sync.