There are some prerequisites to be aware of before setting up High Availability (HA):

General

  • When configuring a HA pair - both units must be the same model, have the same firmware version, and have the same license type.
  • Ensure to Set the Partner Shared Secret.
  • Latency on the link between the two LoadMasters must be below 100 milliseconds.
  • Ensure that any switches have Internet Group Management Protocol (IGMP) snooping disabled.
  • Ensure that any switches have Portfast enabled.
  • Multiprotocol Label Switching (MPLS) networks are not supported in a HA setup.
  • Snapshoting or backing up of the virtual machine is not supported. For further information, refer to the Technical Note Backup and Restore.
  • It is required that the two LoadMasters are located on the same subnet.

Hardware-specific

  • If using physical LoadMasters, it is required that the two LoadMasters are:
    • Deployed.
    • In the same physical location.
    • Not located further than 100 meters from each other.
    • Using the same default gateway.

Virtual-specific

If you are setting up Virtual LoadMasters in HA, refer to the following instructions:
  • Hyper-V

    • Ensure that any switches do not prevent MAC spoofing. For example, on Hyper-V, go to the network adapter settings in the Virtual Machine settings and select the Enable MAC address spoofing check box.

      Issue with Hyper-V and HA on a Pair of VLMs

      If you are having problems with Hyper-V and HA on a pair of VLMs, you may need to configure MAC address spoofing. The following Microsoft TechNet article may help you to fix the problem: Configure MAC Address Spoofing for Virtual Network Adapters.

  • VMware

    • Ensure that MAC address changes and Forged transmits are both set to Accept. Ensure this is forced (hard coded) on the port group because any changes to the vSwitch will affect all port groups by default.

    • When using HA and the LoadMasters are on different hosts: To prevent the transmission of RARP packets from being sent every time a Virtual Machine is powered on, set the Notify Switches option to No.

For further information on Virtual LoadMasters, refer to the Hypervisor (Virtual LoadMaster) Installation Guides.

Cloud-specific

If you are setting up cloud-based LoadMasters in HA, refer to the Cloud LoadMaster Installation Guides.