Hi @jomof ,
My understanding is that you are experiencing those missing heartbeat message randomly and the 2 units are directly connected by a cable. You have already attempted the below steps:
- replace the HA cable with a brand new one and issue is still there
- add a second port to the HA config setting and the messages are still there.
I can see that the error is not very frequent, usually when there is a hardware fault those messages are more frequent based on my experience. Did you notice if the message is seen when there is a particular peak in traffic?
Has the traffic increased in the past weeks?
In addition to what my colleague Suraj suggested, please check/monitor the number of sessions especially while the packet lost message is seen.
get sys performance status
get sys performance firewall statistics
diag sys session stat
If you should notice a too high amount of session when the messages are seen, you may try to implement a delay in session synchronization:
config system ha
set session-pickup-delay enable
end
or dedicate a second port just to the session sync ("set session-sync-dev portX").
The article below might help:
https://docs.fortinet.com/document/fortigate/6.0.0/handbook/495912/improving-session-sync-performance
Best regards,