Troubleshooting Tip: HBDEV status shown as DOWN after upgrading one node of HA cluster

[Ted]

Description	This article describes the case when one node of the HA cluster is upgraded to FortiOS 6.4.9 or more, HBDEV status is displayed 'DOWN' in a CLI command output '# get system ha status'. hadev down Even though the heartbeat ports and session sync ports directly connected between both nodes are still up without any error/dropped count and even heartbeat packets(0x8890) are sent/received well each other. Also, service sessions are synchronized well from the primary unit to the secondary one.
Scope	FortiGate.
Solution	The cosmetic problem HBDEV status is shown as 'DOWN' was resolved in 7.4.0:2266, and it is possible to upgrade to the fixed version.