An engineer needs to configure high availability on two Cisco Secure Firewall Threat Defense appliances. Place the configuration steps in the correct sequence. <DragDrop items={["Configure the primary unit for high availability.","Configure failover criteria for health monitoring.","Prepare the two units for high availability.","Configure the secondary unit for high availability."]} slots={[{"answer":"Prepare the two units for high availability.","id":"step1","label":"Step 1"},{"answer":"Configure the primary unit for high availability.","id":"step2","label":"Step 2"},{"answer":"Configure the secondary unit for high availability.","id":"step3","label":"Step 3"},{"answer":"Configure failover criteria for health monitoring.","id":"step4","label":"Step 4"}]} explanation={"An active/standby FTD pair must first be prepared as compatible units connected through the required failover link (and optionally a state link). Configure the primary first so its configuration can be copied or synchronized to the secondary unit. Configure peer and interface health-monitoring criteria afterward to control the conditions that trigger failover.\n\n**Learn more:** [Cisco Secure Firewall Device Manager Configuration Guide, Version 7.7 — High Availability (Failover)](https://www.cisco.com/c/en/us/td/docs/security/firepower/770/fdm/fptd-fdm-config-guide-770/fptd-fdm-ha.html)"} reuse={false} />