I need to exclude alarms that are being sent to UIM via the snmpd probe.
How can I limit the alarms either by host name or expression?
Within snmptd, there is no way to do filtering per se. You can however, redirect alarm messages so that they are delivered to the logmon probe instead of the nas. Using logmon, you can select just the specific messages you want to have sent to the NAS to generate alarms.
To perform this re-direction, turn off the "Convert to NimBUS Alarm" flag and turn on the "Convert to NimBUS SNMP-TRAP message" flag. This causes snmptd probe to publish messages to the "SNMP-TRAP" subject rather than the "alarm" subject.
Next, create an Attach Queue on the hub. You can name the queue whatever you wish. Set the subject to "SNMP-TRAP". This will cause the messages from snmptd to be gathered into this queue.
Finally, configure logmon to read from the attach queue that you created. Logmon will read the messages line by line, select messages that match the watcher rules and publish those messages on the alarm subject (which the NAS is subscribing to).