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Giorgio_Serafin's avatar
Giorgio_Serafin
Icon for Altocumulus rankAltocumulus
Jul 19, 2022

device state after loss of connection

hi, during the preparation tests I came across this question that left me perplexed:

In an active-standby HA configuration,  all connectivity between the two devices is suddenly lost.

What are the resulting device state:

A) active standby 

B) active active 

C) unavailable unavailable

D) active unavailable

 

for me the correct answer is B, but I'm not sure.

  • Both Units will be in an Active/Active state. This is because the watchdog process will not be able to connect with HA Peer and the unit will become active. Have faced this scenario during device upgrades.

     

  • Hi,

     

    So to answer your question, it depends on which communication channels are down. If all channels including the HA, then the boxes will work as Active-Active since each box will claim the Active role since there is no communication with the peer. This will cause something called Split-Brain and will definitely cause service interruption.

    If the HA channel is still up and both devices can reach each other, then the Active box will be determined upon the HA Active Election Criteria. You can check this reply on another cummunity thread explaining the election process.

  • Hi Giorgio,

    Don't mind me to share some idea for your reference.

    I think the answer is B) Active Active too.

    If you encountering the situation on BIG-IP hardware platform, all connectivity between HA-peer units lost to cause no communication Device Connectivity (Config Sync, Failover unicast...).

    But both units failover port connected, the HA connectivity lost still keep Active Standby state.


    Thanks and Best Regards,
    Alvin Ng

  • Emad's avatar
    Emad
    Icon for Cirrostratus rankCirrostratus

    Both Units will be in an Active/Active state. This is because the watchdog process will not be able to connect with HA Peer and the unit will become active. Have faced this scenario during device upgrades.