SNMP Trap Not Triggering Alert in Nagios XI

[roseblack]

Hi everyone,

I'm currently using Nagios XI (version 5.11.0) and trying to set up SNMP trap-based alerts for a network switch (Cisco Catalyst 2960). I’ve configured the device to send traps to the Nagios server, and I can confirm that the traps are being received (they appear in /var/log/snmptrapd.log).

However, the issue is that Nagios XI is not generating any alerts or associating these traps with a host/service. I’ve already:

Enabled and configured SNMP Trap Interface
Added the MIB files for the device
Restarted snmptrapd and Nagios services
Checked permissions on /var/spool/snmptt/

Despite this, no alerts are triggered in the dashboard.

Is there a specific step I might be missing to map incoming traps to services, or any common misconfiguration that could cause this behavior?

Thanks!

[kg2857]

What do the snmptt logs say?
What's in unconfigured objects?
Have you created the switch host?
Have you created an "SNMP Traps" service and added the host to it?
I searched for a doc: https://assets.nagios.com/downloads/nag ... ios_XI.pdf

[alexwilliams9811]

Yeah, sounds like the trap is reaching snmptrapd but not fully processed.
I’d check a couple quick things:
Do you see anything in /var/log/snmptt/snmptt.log? If not, traps aren’t getting passed to snmptt.
Make sure you have matching OIDs in snmptt.conf (no EVENT = no alert).
Confirm there’s an SNMP Trap service linked to the host in XI.
If any step in the chain breaks (snmptrapd → snmptt → XI → service), you’ll get exactly this behavior.