Before 9.x, you synchronized 3-DNS Controllers (the precursor to Global Traffic Manager) through the use of sync groups. A sync group contained two components: a principal 3-DNS Controller, and one or more receiver 3-DNS Controllers. When you created a sync group, you specified which of the 3-DNS Controllers you wanted to use as the principal system. Any configuration changes you made on that system were then distributed to the secondary 3-DNS Controllers on the network.
With the 9.x line of Global Traffic Manager, specific sync groups no longer exist. Instead, Global Traffic Manager systems reside in more generalized collections, called synchronization groups. Although the names are similar, there are significant feature changes. For example, in these groups, all Global Traffic Manager systems have the same rank; in other words, the principal/receiver hierarchy present in the 4.x line no longer exists. This change allows you to modify the Global Traffic Manager settings from any system; these changes are then sent to all other Global Traffic Managers within the same synchronization group.
To be part of a synchronization group, a Global Traffic Manager:
The synchronization operations in 9.x operate in the following manner:
This process ensures the rapid distribution of Global Traffic Manager settings to any other systems that belong to the same synchronization group.
One exception to this process occurs when you add a new Global Traffic Manager to the network. In this scenario, there is a chance that the timestamp of the new systems configuration file is newer than the files on the already-installed Global Traffic Manager. If you enabled synchronization at this point, the unconfigured configuration file would be distributed to the existing Global Traffic Managers, effectively removing your existing configurations.
You can avoid the accidental synchronization of an unconfigured configuration file to existing Global Traffic Managers through the use of the gtm_add script. This script acquires the configuration file from an existing Global Traffic Manager and applies it to the new system. As a result, the new system has the current configuration for your network.
This implementation focuses on the fictional company, SiteRequest. Currently, the SiteRequest network has two data centers: one located in New York; the other in Los Angeles.
Until recently, SiteRequest had a single Global Traffic Manager located at the New York data center, with an IP address of 192.168.5.199. However, recent increases in DNS traffic have prompted the integration of a new Global Traffic Manager at the Los Angeles data center. These two Global Traffic Managers must belong to the same synchronization group, allowing changes made to one system to transfer over to the other. For the purposes of this solution, both Global Traffic Managers are the same version, and the the Global Traffic Manager in New York is already active and communicating with the rest of the network.
At this point in the example, the new Global Traffic Manager is connected to the network and assigned the IP address, 10.10.5.25. SiteRequest also has a data center object defined on the Global Traffic Manager located in New York, and has named this new data center: Los Angeles Data Center. This data center contains the various BIG-IP systems that reside in Los Angeles. Finally, you have two Local Traffic Managers; one at each data center. The Local Traffic Manager in New York has an IP address of 192.168.5.10; the one in Los Angeles has an IP address of 10.10.5.20.
The tasks you must complete to add a new Global Traffic Manager to a synchronization group are:
The first task you must accomplish is adding the Los Angeles Global Traffic Manager to the New York Global Traffic Manager.
For the next step, you need to enable the Synchronization option and assign an appropriate name for the synchronization group. For this solution, the synchronization group name is North America.
Next, you need to have the new Global Traffic Manager acquire the settings established on an existing Global Traffic Manager. In this example, the Global Traffic Manager in Los Angeles acquires the configurations established at the New York data center. You must do this before you attempt to synchronize these systems; otherwise, you run the risk of having the new Global Traffic Manager, which is unconfigured, replace the configuration of the New York system. To acquire the configuration files, you run the gtm_add script.
At this point, both Global Traffic Managers share the same configuration. In addition, they also belong to the same synchronization group, because the gtm_add script copied the settings from the existing Global Traffic Manager to the new Global Traffic Manager.
With the new unit added to the existing unit, you can now access the new system and run the bigip_add script. This script exchanges SSL certificates so that each system is authorized to communicate with the other. In this example, you run this script from the Global Traffic Manager in the Los Angeles data center.