3.1.7.1 Sending a DHCP Failover UPDREQ Message
When a failover endpoint transitions to the RECOVER or POTENTIAL-CONFLICT state as shown in the Failover state machine figure in section 3.1.1, the failover endpoint MUST send an UPDREQ message to its failover partner server. This behavior is as specified in [IETF-DHCPFOP-12] sections 7.3.1, 9.5, and 9.10 and is unchanged by the extensions specified in this document.