If you are experiencing problems with HA, confirm that:

  • The Partner Shared Secret matches in both the active and standby unit. You can find this secret in the following locations:
    • Regular/shared WUI: Certificates & Security > Remote Access
    • Local WUI (of a configured HA unit): Local Administration > Remote Access
  • The two LoadMasters are on the same subnet.

  • For each Network Interface Card (NIC) that has Use for HA checks enabled, the link status shows as connected.
  • The two units can ping each other and their default gateway. (The ping options are available in System Configuration > Troubleshooting.)
  • Both units have the same time. Set both units to use the same NTP server and correct time zone. (The date and time options are available in Local Administration > Date/Time.)

  • Unit 1 is set to HA (First) Mode. Unit 2 is set to HA (Second) Mode. The HA Virtual ID is the same on both units.

In terms of the network switch settings:

  • Confirm that Promiscuous mode and PortFast are enabled.
  • If HA is configured for multicast traffic (that is, if Use Broadcast IP address is disabled on the LoadMaster HA Parameters screen), then:

    • Confirm that the switch allows multicast traffic

    • Confirm that settings that block multicast traffic, such as 'IGMP snooping', are disabled on the switch.

Sometimes there are logs relating to HA, such as:

<date> <LoadMasterHostName> ucarp[2193]: Bad digest - md2=[xxxxx...] md=[xxxxx...]
- Check vhid, password and virtual IP address

For example:

Jul 13 17:47:10 Kemp_1 ucarp[2193]: Bad digest - md2=[31084da3...] md=[20dcd914...] - Check vhid, password and virtual IP address

The most common reasons for this error are as follows:

  • There is another device on the network with the same HA Virtual ID. The LoadMasters in a HA pair should have the same HA Virtual ID. It is possible that a third device could be interfering with these units. As of LoadMaster firmware version 7.2.36, the LoadMaster selects a HA Virtual ID based on the shared IP address of the first configured interface (the last 8 bits). You can change the value to whatever number you want (in the range 1 - 255), or you can keep it at the value already selected.
  • An interface used for HA checks is receiving a packet from a different interface/appliance. If the LoadMaster has two interfaces connecting to the same switch, with Use for HA checks enabled, this can also cause these error messages. Disable the Use for HA checks option on one of the interfaces to confirm the issue. If confirmed, either leave the option disabled, or move the interface to a separate switch.