In preparation for a maintenance task, an LTM Specialist performs a "Force to Standby" on LTM device Unit 1. LTM device Unit 2 becomes active as expected.
The maintenance task requires the reboot of Unit 1. Shortly after the reboot is complete, the LTM Specialist discovers that Unit 1 has become active and Unit 2 has returned to standby.
What would cause this behavior?
The behavior described is due to the configuration of a traffic group with Auto Failback, where Unit 1 is set as the default device. Auto Failback ensures that when a unit is rebooted and comes back online, it will automatically take over as the active device if it was the designated default. This leads to Unit 1 becoming active again after the reboot.
C - Correct You must configure Failover Method for Failover using Preferred Device Order and then Load Aware if you would like to use the Auto Failback feature. Log in to the Configuration utility. Device Management => Traffic Groups => select your Traffic Group. From the Failover Method list, select a failover method: Failover using Preferred Device List and then Load Aware Then enable Always Fallback to First Device if it is Available. https://my.f5.com/manage/s/article/K45720082