We tested in lab environment what happens when a devices changes it status from reachable to unreachable and we observed that only the reachability status is changed to "Not reachable", but the contact status is still "UP". For SNMP failing device as we had, contact status should change to "Management agent lost". Can you explain why this happens?
Using native SNMP Agent.
.Release : 3.7
There are two Linux servers in the environment, one works OK and the other did not work as expected. We narrowed down the issue to native SNMP agent issues. The other server that is working is using SystemEDGE Agent. Try a newer SNMP agent, if possible. If the results are the same then install systemEDGE Agent.