Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

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ParmessanCheese's avatar
ParmessanCheese
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Mar 05, 2024

LTM/GTM HA Configuration

Hi, I would like to seek your help regarding my implementation for F5 Redundant GTM/LTM set up.   I have 1 pair of LTM/GTM appliance running as Active/Standby HA Pair with GTM enabled on both. When...
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Paulius's avatar
Paulius
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Mar 05, 2024

ParmessanCheese Would you mind sharing your configuration when HA is in place? Based on what you are stating you might have your F5s configured in active/active and then new device does not have network connectivity so the Virtual Servers it is responsible for are down.

ParmessanCheese's avatar
ParmessanCheese
Icon for Nimbostratus rankNimbostratus
Mar 05, 2024

Hi Paulius

 

Thank you very much for your kind response for my question.

 

I have two virtual F5 devices LTM#1 (active) and LTM#2 (standby) in HA pair. Then we decided to activate the GTM license on both devices and plan to configure DNS load balancing. 

 

I started my config on box 1 (LTM#1/GTM#1)

I created data center - "Data_Center_A", then created server "Data_Center_A_Server" and added a device "LTM#1" and it automatically pulled the virtual server list from LTM#1. 

 

But when I added "LTM#2" as the back up device under "Data_Center_A_Server", some of the virtual server went down and I have a feeling that the GTM is communicating with some of the servers on the backup side instead of communicating with the active device since when I rebooted the secondary (backup) device, the virtual servers went up. Then went down again once the backup device went online.

 

Hope this info helps.. :)