When reviewing status for a Device in Performance Management different values are seen.
In the Data Aggregator Monitored Devices Inventory, on the Details tab for the device we see Status: Up / Green.
On the Context Report Details pane for the device we see: Not Reachable / Red
According to a Trend report for Reachability showing 0% and ping failure from the Data Collector CLI to the device IP shows the Details pane in Context Report is correct.
Why is the DA Details pane status Up incorrect?
DX NetOps Performance Management release r20.2.3 or r3.7.16 and earlier
Due to known defect DE480665
A change to Reachability collected via SNMP was made to return 0 for values instead of REQUEST_TIMED_OUT when the device is no longer Reachable. Since it's considered a valid SNMP request/response pair, we don't mark the device MGMT LOST because there was that one successful SNMP response in the poll response returned from DC to DA.
The fix will correct it so the correct state in the DA details tab is shown. The fix for defect DE480665 is included in the r21.2.1 release. Upgrade to r21.2.1 or newer releases for a permanent solution.
Possible workarounds to the problem suggested are the following. Note these are not tested.