You can configure BIG-IP® DNS in a redundant system configuration, which is a set of two BIG-IP DNS systems: one operating as the active unit, the other operating as the standby unit. If the active unit goes offline, the standby unit immediately assumes responsibility for managing DNS traffic. The new active unit remains active until another event occurs that would cause the unit to go offline, or you manually reset the status of each unit.
Perform the following tasks to configure a BIG-IP DNS redundant system configuration.
Before you begin, ensure that the Setup utility was run on both devices. During the Setup process, you create VLANs internal and external and the associated floating and non-floating IP addresses, and VLAN HA and the associated non-floating self IP address. You also configure the devices to be in an active-standby redundant system configuration.