Manual Chapter : Setting Up a BIG-IP GTM Redundant System Configuration

Applies To:

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  • 11.5.10, 11.5.9, 11.5.8, 11.5.7, 11.5.6, 11.5.5, 11.5.4, 11.5.3, 11.5.2, 11.5.1
Manual Chapter

Overview: Configuring a BIG-IP GTM redundant system

You can configure BIG-IP Global Traffic Manager (GTM) in a redundant system configuration, which is a set of two BIG-IP GTM 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.

Task Summary

Perform the following tasks to configure a BIG-IP GTM 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.

Defining an NTP server

Define a Network Time Protocol (NTP) server that both BIG-IP GTM systems use during configuration synchronization.
Important: Perform these steps on both the active and standby systems.
  1. On the Main tab, click System > Configuration > Device > NTP. The NTP Device configuration screen opens.
  2. In the Time Server Lookup List area, in the Address field, type the IP address of the NTP that you want to add. Then, click Add.
    Note: If you did not disable DHCP before the first boot of the BIG-IP system, and if the DHCP server provides the information about your NTP server, then this field is automatically populated.
  3. Click Update.

Creating listeners to identify DNS traffic

Create listeners to identify the DNS traffic that BIG-IP GTM handles. The best practice is to create four listeners: one with an IPv4 address that handles UDP traffic, and one with the same IPv4 address that handles TCP traffic; one with an IPv6 address that handles UDP traffic, and one with the same IPv6 address that handles TCP traffic.
Note: DNS zone transfers use TCP port 53. If you do not configure listeners for TCP the client might receive the error: connection refused or TCP RSTs.
If you have multiple GTM systems in a device group, perform these steps on only one system.
  1. On the Main tab, click DNS > Delivery > Listeners. The Listeners List screen opens.
  2. Click Create. The Listeners properties screen opens.
  3. In the Name field, type a unique name for the listener.
  4. For the Destination setting, in the Address field, type an IPv4 address on which GTM listens for network traffic.
  5. In the Service area, from the Protocol list, select UDP.
  6. Click Finished.
Create another listener with the same IPv4 address and configuration, but select TCP from the Protocol list. Then, create two more listeners, configuring both with the same IPv6 address, but one with the UDP protocol and one with the TCP protocol.

Defining a data center

On BIG-IPGTM, create a data center to contain the servers that reside on a subnet of your network.
  1. On the Main tab, click DNS > GSLB > Data Centers. The Data Center List screen opens.
  2. Click Create. The New Data Center screen opens.
  3. In the Name field, type a name to identify the data center.
    Important: The data center name is limited to 63 characters.
  4. In the Location field, type the geographic location of the data center.
  5. In the Contact field, type the name of either the administrator or the department that manages the data center.
  6. From the State list, select Enabled.
  7. Click Finished.
Now you can create server objects and assign them to this data center.
Repeat these steps to create additional data centers.

Defining a server to represent each BIG-IP system

Ensure that the data centers where the BIG-IP GTM systems reside exist in the configuration.
Using this procedure, create two servers on the active BIG-IP system, one that represents the active system and one that represents the standby system.
Important: Perform this procedure on only the active system.
  1. On the Main tab, click DNS > GSLB > Servers. The Server List screen opens.
  2. Click Create. The New Server screen opens.
  3. In the Name field, type a name for the server.
    Important: Server names are limited to 63 characters.
  4. From the Product list, select BIG-IP System (Redundant). The server type determines the metrics that the system can collect from the server.
  5. In the Address List area, add the IP address of the server.
    Important: You must use a self IP address for a BIG-IP system; you cannot use the management IP address.
  6. In the Address List area, add the IP addresses of the back up system using the Peer Address List setting.
    1. Type an external (public) IP address in the Address field, and then click Add.
    2. Type an internal (private) IP address in the Translation field, and then click Add.
    You can add more than one IP address, depending on how the server interacts with the rest of your network.
  7. From the Data Center list, select the data center where the server resides.
  8. From the Virtual Server Discovery list, select Disabled.
  9. Click Create. The Server List screen opens displaying the new server in the list.

Enabling global traffic configuration synchronization

Enable global traffic configuration synchronization options and assign a name to the GTM synchronization group.
  1. On the Main tab, click DNS > Settings > GSLB > General. The General configuration screen opens.
  2. Select the Synchronize check box.
  3. In the Group Name field, type the name of the synchronization group.
  4. In the Time Tolerance field, type the maximum number of seconds allowed between the time settings on this system and the other systems in the synchronization group. The lower the value, the more often this system makes a log entry indicating that there is a difference.
    Tip: If you are using NTP, leave this setting at the default value of 10. In the event that NTP fails, the system uses the time_tolerance variable to maintain synchronization.
  5. Select the Synchronize DNS Zone Files check box.
  6. Click Update.

Running the gtm_add script

You must run the gtm_add script from the standby system.
Note: You must perform this task from the command-line interface.
  1. On the new BIG-IP GTM system, log in to the command-line interface.
  2. Type gtm_add, and press Enter.
  3. Press the y key to start the gtm_add script.
  4. Type the IP address of the existing GTM system, and press Enter.
The gtm_add script acquires configuration data from the active system; once this process completes, you have successfully created a redundant system consisting of two GTM systems.