Select Other name servers
from the Name servers section (A).
Enter the Primary name server
address in the Name Server 1 text box. Select 1&1 name server
from the Secondary name server drop-down menu. Please note that using the 1&1 name servers as a backup in the case of an outage by your primary name server, will result in traffic being directed to the IP address of your 1&1 package.
Name Server Settings menu