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Barracuda Load Balancer

How to Replace a Barracuda Load Balancer in a High Availability Environment

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High availability (HA) is an advanced feature; contact Barracuda Networks Technical Support before replacing a Barracuda Load Balancer in a cluster.

The steps for replacing a Barracuda Load Balancer differ based on whether the system is the Primary or the Secondary device in the cluster.

The High Availability (HA) environment is available on the Barracuda Load Balancer 340 and higher; note that both Barracuda Load Balancers in HA must be the same model and on the same firmware.

Replace the Primary System in a High Availability Environment

This section describes the most common scenarios for replacing the Primary system in HA.

Because the Primary system is offline during replacement, you must schedule downtime when replacing the Primary system in HA.

Select the scenario that best fits your use case, and complete the associated steps when replacing the Primary system in an HA environment.

Scenario 1. New Replacement Primary Device

Follow the steps in this procedure carefully; on firmware version 4.1.0.034 or higher, it is necessary to perform a hot swap and delete the Primary device from the Secondary device configuration at the end of this procedure to avoid wiping out the configuration of the Secondary device.

Figure 1. New Primary Device Replacement.

HA-scenario01.jpg

  1. Back up the system configuration on the Secondary device.

    Note that the Secondary device must remain active since the Primary device is down during this replacement procedure.

  2. Complete the following steps on the Secondary device:
    1. Log in to the Secondary device, and navigate to the ADVANCED > Backup page.
    2. In the Configuration Backup section, click Backup to download a backup to your desktop. 
  3. Install the new replacement Primary device and assign the WAN IP address of your old Primary device to the new Primary device. Verify the new Primary device is on the same firmware version as the existing devices.
  4. Once the new device is installed, log in to the Primary System, go to the ADVANCED > Backup page, and complete the following steps:
    1. In the Restoring Backups section, click Browse after the Restore Backup File; navigate to and select the configuration backup saved to your desktop.
    2. Click Upload to upload the configuration backup file to the Primary device.

      Connections on the primary and secondary devices may go down intermittently during this procedure.

  5. On the Primary device, go to the ADVANCED > High Availability page, and configure all attributes in the exact same manner as those on the Secondary device; the Cluster Shared Secret must match exactly.
  6. On the Secondary device, navigate to the ADVANCED > High Availability page, and complete the following steps:
    1. In the Clustered Systems section, delete the IP address of the old Primary device; the system refreshes and wipes out all of the configuration settings.
    2. Once the device is back online, go to the BASIC > IP Configuration page and set the domain name.
    3. Navigate to the ADVANCED > High Availability page, and under Clustered Systems, assign the IP address of the Primary device, and click Join Cluster. 

Scenario 2. Activate the New Primary Device in an Isolated Network

Figure 2. Isolated Network Environment.

HA-scenario02.jpg

  1. Back up the system configuration on the Secondary device.

    Note that the Secondary device must remain active until step 6 in this procedure.

  2. Log in to the Secondary device, and navigate to the ADVANCED > Backup page.
  3. In the Configuration Backup section, click Backup to download a backup to your desktop.
  4. Install the new replacement Primary device in an isolated network, and complete the following steps:
    1. Go to the ADVANCED > Backup page on the Primary device, and in the Restoring Backups section, click Browse after the Restore Backup File.
    2. Navigate to and select the configuration backup saved to your desktop in step above.
    3. Click Upload to upload the configuration backup file to the Primary device.
    4. Assign the WAN IP address of the old Primary device to the new Primary device.
  5. Verify the configuration on the new Primary device.
  6. After verifying the configuration, complete the following at the same time:
    • Shutdown the Secondary device, and
    • Connect and power up the new Primary device to the production network.
  7. Put the Secondary device in an isolated network. 
  8. On the Primary device, go to the ADVANCED > High Availability page, and configure all attributes in the exact same manner as those on the Secondary device; the Cluster Shared Secret must match exactly.
  9. Remove the Secondary device from the cluster by deleting the IP address of the old Primary device from the Clustered Systems section. 
  10. Put the Secondary device back in the production network.

Replace the Secondary System in a High Availability Environment

Figure 3. Secondary System Replacement.

HA-scenario03.jpg

  1. Remove the old Secondary device using the instructions in the article How to Remove a Barracuda Load Balancer from a High Availability Environment.
  2. Install the new replacement Secondary device using the Barracuda Load Balancer Quick Start Guide.
  3. Once the new device is installed, follow the steps in the article How to Configure the Barracuda Load Balancers for High Availability to complete the system replacement in the HA configuration.

    When replacing a system in a cluster, both systems must be on the same firmware version.

 

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