When you are working with more than one 3-DNS Controller in your network, and you want the controllers to load balance to the same virtual servers, you can create your entire configuration on one controller and then add the second controller using the 3dns_add script. The 3dns_add script copies the entire configuration from the first controller onto the second controller, and synchronizes all of the settings between the controllers. When you are finished, the first controller acts as the principal controller in the sync group, and the second controller becomes a receiver controller. (For more information about sync groups, see Working with sync groups, on page 2-37 .)
The following sections of this chapter describe the procedures you follow to add a 3-DNS Controller into a network that already has at least one 3-DNS Controller configured and working properly. If you are adding the first 3-DNS Controller to your network, refer to Chapter 2, Essential Configuration Tasks .
Note: If you are adding a second 3-DNS Controller to your network but do not want it to be in the same sync group as your first controller, or you want the second 3-DNS Controller to load balance to a different set of virtual servers, then do not use the 3dns_add script.
Before you run the 3dns_add script on any additional 3-DNS Controllers you are adding to your network, you should complete the following tasks:
Completing these tasks ensures that when you run the 3dns_add script, the second 3-DNS Controller successfully copies the configuration information from the first 3-DNS Controller.
You can find detailed instructions on installing the 3-DNS Controller hardware in the Installation Guide. The Installation Guide also includes detailed instructions on running the First-Time Boot utility. When you have finished this part of the setup for the second controller, do not make any other changes to the configuration.
Note: If you are working with the 3-DNS module on the BIG-IP Controller, please refer to the BIG-IP Installation Guide, which is included in the Administrator Kit. If you are working with the standalone 3-DNS Controller, please refer to the 3-DNS Installation Guide, which is included in the Administrator Kit.
Once you have installed the hardware and run the First-Time Boot utility on the new controller, you add its configuration information to the existing 3-DNS Controller. The existing controller becomes the principal controller in the sync group once you run the 3dns_add script on the new controller.
c) Check the controller you just defined and click Add.
The new controller becomes a receiver in the sync group of the existing controller.
You have now successfully added the new controller to the existing controller's configuration. The following sections describe how to run the 3dns_add script and verify the configuration.
You can run the 3dns_add script on the new 3-DNS Controller either using a remote secure shell session, or using a monitor and keyboard connected locally to the controller.
Once the script finishes, we recommend that you verify the following aspects of your configuration:
You can perform these verification tasks on any of the controllers in the sync group. The following sections describe the verification process in detail.
If the virtual servers belonging to the wide IP appear in a pattern that reflects the load balancing mode you selected, you have successfully configured your 3-DNS Controllers. Note that you can repeat the previous procedure for each wide IP you configured.
Note: This is the only verification task that you perform from the command line. The nslookup utility is part of DNS distributions. For more information on how to use the nslookup utility, please refer to the book, DNS and BIND, by Albitz and Liu.