Click Settings, and the HA Policy Settings page will appear.

HA Policy: When Enable is selected, you can configure HA policy settings.

Mode: Specify the HA mode. You can select Active/Standby or Active/Active.

Control Link: Responsible for transmitting HA heartbeat packets, which include local HA settings, local HA status, and other information. After configuring the control link using the same interface for the local and peer devices, the control link determines the active and standby devices and synchronizes settings from the active device to the standby device to establish an HA mode. You can use an aggregate interface for the control link and ensure that the interfaces of the active and standby devices are the same.

Data Link (Optional): Responsible for synchronizing data, such as sessions. When no data link is set or when the data link fails, the control link takes the place of the data link. When the control link fails, the data link transmits heartbeat packets.

Advanced: Click Settings to customize advanced settings, as shown in the following figure.

Priority: Specify the priorities of the interfaces selected in the interface list. Higher values indicate higher priorities. Enable Proactive Preemption after setting the priority because priority settings must work with this function. Assume that two devices are in active/standby mode (one device is active whereas the other is inactive as a standby), and you assign a priority of 90 to Device A (preemption enabled) and a priority of 80 to Device B (preemption enabled or disabled). When Device A fails, Device B becomes active. When Device A recovers, Device A replaces Device B as the active device, and Device B becomes standby.

Proactive Preemption: Specify whether to allow the failed active device to become the active device again after it recovers. This function must work with the Priority settings.

Preemption Delay: Specify the preemption delay, which is set to 300 seconds by default.

Virtual IP Addresses: Specify virtual IP addresses for service interfaces to enable communication. The virtual IP addresses are synchronized from the active device to the standby device and are only assigned by the active device. During a failover, the new active device assigns the virtual IP addresses while the new standby device removes them. To add a virtual IP address, click Add, as shown in the following figure.

Monitored Object Management: Specify the interfaces and links to be monitored. To set objects to be monitored, click Manage, as shown in the following figure.

Interface Monitoring: Specify the interfaces to be monitored. You can add multiple interface groups and assign multiple interfaces to each group. For each interface group, you can select All fail or One fails as the Failure Trigger for failover. To add a group, click Add under the Interface Monitoring tab, as shown in the following figure.

Link Monitoring: This setting takes effect when the link state detection on the Objects > Link State Detection page is referenced. The interfaces selected here are checked for possible issues with them or their links. If you do not select Link Monitoring, the system only checks the status of the interfaces specified in Interface Monitoring. A failover is not triggered until the physical interface is down. You can add multiple link groups and assign multiple links to each group. For each link group, you can select All fail or One fails as the Failure Trigger for failover. To add a group, click Add under the Link Monitoring tab, as shown in the following figure.

Monitored Object: Display the monitoring groups specified in Monitored Object Management. Failovers are triggered based on the specified conditions.