Manual Chapter : Integrating BIG-IP DNS Into a Network with BIG-IP LTM Systems

Applies To:

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BIG-IP DNS

  • 12.1.5, 12.1.4, 12.1.3, 12.1.2, 12.1.1, 12.1.0
Manual Chapter

Integrating BIG-IP DNS Into a Network with BIG-IP LTM Systems

Overview: Integrating BIG-IP DNS (formerly GTM) with other BIG-IP systems on a network

You can add BIG-IP® DNS systems to a network in which BIG-IP® Local Traffic Manager™ (LTM®) systems and BIG-IP Link Controller™ systems are already present. This expands your load balancing and traffic management capabilities beyond the local area network. For this implementation to be successful, you must authorize communications between the systems.

Note: The BIG-IP DNS devices in a BIG-IP DNS synchronization group, and the LTM and Link Controller devices that are configured to communicate with the devices in the BIG-IP DNS synchronization group must have TCP port 4353 open through the firewall between the systems. The BIG-IP devices connect and communicate through this port.

About iQuery and communications between BIG-IP systems

The gtmd agent on BIG-IP® DNS uses the iQuery® protocol to communicate with the local big3d agent, and the big3d agents installed on other BIG-IP systems. The gtmd agent monitors both the availability of the BIG-IP systems, and the integrity of the network paths between the systems that host a domain and the local DNS servers that attempt to connect to that domain.

Example of communications between big3d and gtmd agents

Communications between big3d and gtmd agents using iQuery

Task summary

To authorize communications between BIG-IP® systems, perform the following tasks on the BIG-IP DNS system that you are adding to the network.

Defining a data center

On BIG-IP®DNS, 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 BIG-IP DNS systems

Ensure that at least one data center exists in the configuration before you start creating a server.
On BIG-IP® DNS, create a server object to represent the BIG-IP DNS system itself.
  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.
  5. In the Address List area, add the non-floating IP addresses of the server.
    You can add more than one IP address, depending on how the server interacts with the rest of your network.
    Important: You must use a self IP address for a BIG-IP system; you cannot use the management IP address.
  6. From the Data Center list, select the data center where the server resides.
  7. In the Health Monitors area, assign the bigip monitor to the server by moving it from the Available list to the Selected list.
  8. From the Virtual Server Discovery list, select how you want virtual servers to be added to the system.
    Option Description
    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.
  9. In the Virtual Server List area, if you selected Disabled from the Virtual Server Discovery list, specify the virtual servers that are resources on this server.
    1. In the Name field, type the name of the virtual server.
    2. In the Address field, type the IP address of the virtual server.
    3. From the Service Port list, select the port the server uses.
    4. Click Add.
  10. From the Link Discovery list, select how you want links to be added to the system.
    Option Description
    Disabled The system does not use the discovery feature to automatically add links. 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 links to the system.
    Enabled The system uses the discovery feature to automatically add links. Use this option for a BIG-IP DNS/LTM combo system when you want BIG-IP DNS to discover links.
    Enabled (No Delete) The system uses the discovery feature to automatically add links and does not delete any links that already exist. Use this option for a BIG-IP DNS/LTM combo system when you want BIG-IP DNS to discover links.
  11. Click Create.
    The Server List screen opens displaying the new server in the list.

Defining BIG-IP LTM systems

On DNS, define servers that represent the LTM® systems in your network.
  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.
  5. In the Address List area, add the non-floating IP addresses of the server.
    You can add more than one IP address, depending on how the server interacts with the rest of your network.
    Important: You must use a self IP address for a BIG-IP system; you cannot use the management IP address.
  6. From the Data Center list, select the data center where the server resides.
  7. In the Health Monitors area, assign the bigip monitor to the server by moving it from the Available list to the Selected list.
  8. From the Virtual Server Discovery list, select how you want virtual servers to be added to the system.
    Option Description
    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.
  9. In the Virtual Server List area, if you selected Disabled from the Virtual Server Discovery list, specify the virtual servers that are resources on this server.
    1. In the Name field, type the name of the virtual server.
    2. In the Address field, type the IP address of the virtual server.
    3. From the Service Port list, select the port the server uses.
    4. Click Add.
  10. From the Link Discovery list, select how you want links to be added to the system.
    Option Description
    Disabled The system does not use the discovery feature to automatically add links. 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 links to the system.
    Enabled The system uses the discovery feature to automatically add links. Use this option for a BIG-IP DNS/LTM combo system when you want BIG-IP DNS to discover links.
    Enabled (No Delete) The system uses the discovery feature to automatically add links and does not delete any links that already exist. Use this option for a BIG-IP DNS/LTM combo system when you want BIG-IP DNS to discover links.
  11. Click Create.
    The Server List screen opens displaying the new server in the list.

Running the big3d_install script

Determine the self IP addresses of the BIG-IP® systems that you want to upgrade with the latest big3d agent. Ensure that port 22 is open on these systems.
Run the big3d_install script on the DNS system you are adding to your network. This upgrades the big3d agents on the other BIG-IP systems on your network. It also instructs these systems to authenticate with the other BIG-IP systems through the exchange of SSL certificates. For additional information about running the script, see SOL1332 on AskF5.com (www.askf5.com).
Note: You must perform this task from the command-line interface.
Important: All target BIG-IP systems must be running the same or an older version of BIG-IP software.
  1. Log in as root to the BIG-IP DNS system you are adding to your network.
  2. Run this command to access tmsh:
    tmsh
  3. Run this command to run the big3d_install script:
    run gtm big3d_install <IP_addresses_of_target BIG-IP_systems>
    The script instructs BIG-IP DNS to connect to each specified BIG-IP system.
  4. If prompted, enter the root password for each system.
The SSL certificates are exchanged, authorizing communications between the systems. The big3d agent on each system is upgraded to the same version as is installed on the BIG-IP DNS system from which you ran the script.

Implementation result

You now have an implementation in which the BIG-IP® systems can communicate with each other. DNS can now use the other BIG-IP systems when load balancing DNS queries, and can acquire statistics and status information for the virtual servers these systems manage.