SNMP Traps: Moving from Previous Enterprise Manager Releases to 12c and Greater

Note:

When you upgrade from a pre-Enterprise Manager 12c release to 12c and greater, SNMP advanced notification methods defined using previous versions of Enterprise Manager (pre-12c) will continue to function without modification.

For Enterprise Manager 11g and earlier, there were two types of SNMP traps:

  • Alerts

  • Job Status

Beginning with Enterprise Manager 12c there is now a single, comprehensive SNMP trap type that covers all available event types such as metric alerts, target availability, compliance standard violations, or job status changes. For more information about pre-12c to 12c SNMP trap mappings, see SNMP Trap Mappings. Traps will conform to the older Enterprise Manager MIB definition. Hence, pre-Enterprise Manager 12c traps will continue to be sent. See SNMP Trap Mappings for more information.

Also, for Enterprise Manager 12c, size of SNMP trap has increased in order to accommodate all event types and provide more comprehensive information. By default, the maximum SNMP packet size is 5120 bytes. If the third party system has a limit in the size of SNMP trap it can receive, you can change the default size of SNMP trap that Enterprise Manager sends. To change the default packet size, set this emoms oracle.sysman.core.notification.snmp_packet_length parameter, and then bounce the OMS.

Note:

When limiting the SNMP trap packet size, Oracle recommends not setting the oracle.sysman.core.notification.snmp_packet_length parameter any lower than 3072 bytes (3K).

The Enterprise Manager 12c MIB includes all pre-Enterprise Manager 12c MIB definitions. Hence, if you have an Enterprise Manager 12c MIB in your third party system, you can receive SNMP traps from both pre-Enterprise Manager 12c as well as Enterprise Manager 12c sites. For detailed information on version mapping, see SNMP Trap Mappings.