Nagios Support Forum

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!

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

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.