You can configure BIG-IP® DNS (formerly (GTM)™) systems in collections called BIG-IP DNS synchronization groups. All BIG-IP DNS systems in the same BIG-IP DNS synchronization group have the same rank, exchange heartbeat messages, and share probing responsibility.
Configuration changes to one device in a BIG-IP DNS synchronization group are synchronized incrementally across the devices in the group. That is, only the data that has changed on a BIG-IP DNS device is synchronized to the other devices in the group. Although incremental synchronization is the default behavior, if an incremental synchronization fails, the system automatically performs a full configuration synchronization.
BIG-IP DNS systems in a BIG-IP DNS synchronization group
When you add a BIG-IP® DNS system to a network that contains older BIG-IP DNS systems, the devices can exchange heartbeat messages, even though the BIG-IP software versions are different. However, to add BIG-IP DNS to a configuration synchronization group, you must run the gtm_add script.
Decide to which BIG-IP DNS synchronization group you want to add the BIG-IP DNS system. Make certain that at least one previously-configured BIG-IP DNS belongs to that BIG-IP DNS synchronization group.
|Disabled||The system does not use the discovery feature to automatically add virtual servers. This is the default value. Use this option for a standalone BIG-IP DNS system or for a BIG-IP DNS/LTM® combo system when you plan to manually add virtual servers to the system, or if your network uses multiple route domains.|
|Enabled||The system uses the discovery feature to automatically add virtual servers. Use this option for a BIG-IP DNS/LTM combo system when you want the BIG-IP DNS system to discover LTM virtual servers.|
|Enabled (No Delete)||The system uses the discovery feature to automatically add virtual servers and does not delete any virtual servers that already exist. Use this option for a BIG-IP DNS/LTM combo system when you want the BIG-IP DNS system to discover LTM virtual servers.|
The new BIG-IP® DNS system that you added to the network is a part of a BIG-IP DNS synchronization group. Changes you make to any system in the BIG-IP DNS synchronization group are automatically propagated to all other BIG-IP DNS systems in the group.