SNMP: Trying to understand what Alarm and Alarm Reporting Control Management Information base are used for

Question

I am new to SNMP and have troubles understanding the SNMP requirements of a Java application I am required to implement. I am using openDMK to provide the SNMP support. Please excuse any brutal ignorance in my questions. I have read the RFC specs, but most of the text appear to be gibberish to me.

One requirement is that "SNMP support must be comformable with Alarm MIB (RFC 3877)".

• What does this mean?
• What is Alarm MIB used for?
• Is this related to SNMP Trap/Notification? Reading the RFC specs, I have the feeling that this is about the SNMP Notification/Trap that my application needs to send out to the managers in case something bad occurs (e.g. a threshold was exceeded). If so, I still don't understand what exactly I need to do with this requirement.
  • I will need to define my own application's SNMP Trap definitions (i.e. not using the generic ones). How will my MIB be different now that I need to support Alarm MIB?
  • Is it that, besides sending out a Notification, I need to store that Notification in the Alarm table? If so, what is the purpose of doing so?

• Below is a method from the openDMK library to send out a SNMPv2 Trap:

  public void snmpV2Trap(SnmpOid trapOid, SnmpVarBindList varBindList)

  My understanding of how to use this method is trapOid will refer to the OID of the Notification in my application's MIB and varBindList is any additional parameters to send. So, how/where does Alarm MIB fit into this?

Another requirement is "SNMP support must be comformable with Alarm Reporting Control MIB (RFC 3878)".

• What does this mean?
• What is Alarm Reporting Control MIB used for?
• Any relation to SNMP Trap/Notification?

Thanks a bunch!

Answer 1

SNMP notifications (which include both traps and informs) are a delivery mechanism. Alarms, on the other hand, are an indication of a problem. An alarm problem could stem from many sources and could be about many topics. Thus when an alarm is triggered it will be sent over an SNMP notification.

The alarm MIBs allow a manager to control when and if an alarm should be sent for a given topic.

Having said all that, I agree that reading those particular RFCs is difficult because the text describes high-level nebulous design patterns and the MIBs are very low-level technical details but the middle-level descriptions are missing. Examples would certainly help. Section 6 of 3877 is probably useful after you've read the whole document once or twice.