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Snizri
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Aug 29, 2023

Sync Tests

Hi, I have several sites at work where each site has a DR site, which should go up as soon as there is a disabling fault.
On my normal site there are two virtual machines with F5 installed and in the DR environment there is one machine with F5 which is in DISABLE mode. All three machines are synchronized with the DR site being the only one that is set to DISABLE. I was asked to give a report if and when there is a situation where the F5 on the site goes down, will the F5 on the DR site function properly. What tests should I do, and what should I implement for it to work?

I ran the show /cm sync-status command. And it showed me that all the machines are connected and synchronized with the group.

3 Replies

  • Hi Snizri , 
    so you have one device group contains ( 3 devices in-synced ) >> 2 in the main side and 1 in DR side , Correct ? 

    could you clarify what do you mean by ( DR Device is Disabled ). 
    To Test Sync >> 
    - Open the GUI for each device and make sure that all objects are synced. 

    - If you want to test traffic , and when one of devices become down which device will handle user traffic : 
    Go to traffic group , I assume you only have one traffic group ( which is the default one ) >>> and check the prefered order or ( HA order List ) here is the piece which control your next active device if the current Active down. 

    Let we say it in examples in your scenario : 
    you have : 
    main site ( Bigip_1 " Current Active " , Bigip_2 " Standby" ) 
    DR site    ( Bigip_3 "Standby" ). 

    Go to traffic group >>> you will see two methods of managing failover or selecting which be Active device in failures. 

    - First method : HA order List >> and in this method you order your devices . like this : 
    Bigip_1 ( Active) 
    Bigip_2
    Bigip_3

    if Bigip_1 failed , it will failover to Bigip_2 and Bigip_2 become the Active and handle traffic. 
    if Bigip_1 & Bigip_2 failed >>> Bigip_3 will take the Active role in the device group and handle traffic an so on. 

    - Second method : Load aware >> maybe this is not the widely used one , but it depends on some caculations related to appliance capacity or depending on the quantity of load in this appliance , So based on that will choose the Active device. 
    Also Load aware method used when using a heterogeneous devices so it looks for the most powerful device has the most capacity when failover occure. 

    For more info about that , Please and mandatory to read this article well : https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/bigip-device-service-clustering-admin-11-5-0/8.html 
    to learn how to manage HA failover and which device should handle traffic. 

    Let me know if I missed something , I hope that my comment helps you ! 🙂 

    • Snizri's avatar
      Snizri
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      Thank you for the quick answer 🙂