We monitor several servers, switches, firewalls and UPS's.

Recently, due to a firewall fault, the SNMP request for a server did not respond any more. We attach Notification Profiles when a threshold is reached but no alarm was given because when we don't get a new value, no threshold is reached, so no alarm is triggerd for us.

Yesterday, we got the same issue again with an UPS. The SNMP Requests were not getting any value back (although it worked through the MIB Browser). Removing the UPS, and adding it again solved the SNMP Requests. But again, we only noticed the SNMP request were failing because we didn't get any alarm when the UPS did not receive any power and had to switch to battery.

Is there a documented way to detect if a SNMP Request does not get any value back?

Greetz