An HA pair of LTM devices configured in Active-Standby mode stops responding to traffic and causes an outage. The Active device becomes Standby, but the partner device stays in Standby mode instead of taking over as Active. A reboot and restart of the services brings the LTM device to Active mode for a short time, but then it goes into Standby mode again.
Which two configuration components caused this condition? (Choose two.)
The condition described in the question suggests that the LTM devices are triggering a failover due to network issues but not properly switching roles. VLAN Fail-safe can cause a device to go into Standby mode if it detects a lack of network activity on a specific VLAN, which would explain why the active device goes into Standby mode. Gateway Fail-safe can also result in a device failing over if the optimal gateway becomes unreachable, leading to the scenario where both devices might end up in Standby mode if they cannot detect the gateway. These configuration components match the described symptoms and are likely causes of the condition.
AC - Correct VLAN Fail-Safe: After the failsafe timer expires and the configured action is performed, the device remains in failsafe fault mode and cannot become active until network activity is detected on the VLAN. https://my.f5.com/manage/s/article/K13297 Gateway Fail-Safe: The Failover action is the optimal gateway fail-safe action. You can use the Reboot and Restart All actions when upstream equipment requires the BIG-IP system to drop the links to clear out their Address Resolution Protocol (ARP) cache or cause the interfaces to reset. https://my.f5.com/manage/s/article/K91881543