Trapd

From OpenNMS

Trapd handles the processing of SNMP trap data.

Functionality

Trapd allows OpenNMS to receive snmp traps and turn them into events, and then into alarms and/or notifications, much as Syslogd does for syslog entries.

Availability

"Unknown" - Probably it's been there from the very beginning as it is a central function.

Configuration

trapd-configuration.xml

<?xml version="1.0"?>
    <trapd-configuration snmp-trap-port="162" new-suspect-on-trap="false"/>

The <configuration> element specifies global parameters that specify how Trapd will receive and process snmp traps. This element has the following attributes:

Port, Trapd port (udp) to listen on (Default 162)
New suspect on messages specifies whether Trapd will inject a newSuspect event when it receives an snmp trap originating from a host that cannot be resolved to an existing node managed by OpenNMS. This functionality is equivalent to the same option in Syslogd. New suspects will be queued for discovery by Capsd.

Technical description

The service is built around traditional UDP based snmp traps, and the service is a receiver of traps created by remote devices.

How does it work

Question - What will happen as a snmp trap arrives?

Answer - The message is parsed, the sender compared to known nodes. If the sender is an unknown node and new-suspect-on-trap="true" is configured an event is sent to discover the node. Otherwise the trap is tagged to the correct node, broadcast to eventd, and from there on essentially is an openNMS event.

Question - Event how?

Answer - We convert the snmp trap to an openNMS Event, the matching event as usual is found in the etc/events directory.

I.e. for each trap received, it will get prioritized, categorized and submitted to the eventprocessor for notification or other configured actions.