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The Simple Network Management Protocol (SNMP) Trap plug-in does not send request to a data source, but instead listens for incoming SNMP traps from SNMP agents. The plug-in is a SNMP manager that runs at port 162 when loaded by the Collection Point. If two Collection Points are installed on the same machine, one of the SNMP plug-ins must change its port.

Note

The BMC Service Level Management implementation of the plug-in can only accept version v1 and v2c traps. Version v3 traps are not supported.

Discovery

The plug-in loads landscape information from the snmp.conf configuration file. Every time the discovery method is called, snmp.conf is loaded, thus you do not have to restart the Collection Point to discover new landscape information after snmp.conf is modified.

Following is a sample snmp.conf file: 

# Default status mapping: 0-ok 1-warn 2-alarm 3-offline
# For snmpv1 trap, TrapID is "EnterpriseID GenericTrapNumber SpecificTrapNumber"
# For snmpv2c trap, TrapID is "snmpTrapOID"
# Format 1: label; status/numeric; TrapID; value; TrapID; value;...
# Format 2: label; status[:StatusMapping]/numeric; TrapID; parameterOID;
#	where [:StatusMapping] is in the form of:parameterValue:statusValue:...
#	where statusValue is 0(OK),1(WARN),2(ALARM), or 3(OFFLINE)
# for example, map "on" to OK and "off" to ALARM :on:0:off:2
SNMPAgent	172.18.53.130 172.18.52.141 localhost
# v1 trap, linkup - ok, linkdown - alarm
linkStatusV1; status;	1.3.6.1.4.1.1824 2 0; 0; 1.3.6.1.4.1.1824 3 0; 2
# v2 trap
linkStatusV2; numeric; 1.3.6.1.6.3.1.1.5.3;	100; 1.3.6.1.6.3.1.1.5.4; 200
# Format 1 status example
enterpV1; status; 1.3.6.1.4.1.1824 6 1;	0; 1.3.6.1.4.1.1824 6 2;	2
enterpV2; status; 1.3.6.1.4.1.1824.0.1;	0; 1.3.6.1.4.1.1824.0.2;	2
# Format 2 status example
statusV1; status:on:0:off:2; 1.3.6.1.4.1.1824.1 6 0;
1.3.6.1.4.1.1824.1.0.0.1;
# Format 2 numeric example
numericV1; numeric; 1.3.6.1.4.1.1824.1 6 0; 1.3.6.1.4.1.1824.1.0.0.1;
numericV2; numeric; 1.3.6.1.4.1.1824.1;	1.3.6.1.4.1.1824.1.0.0.1;
SNMPAgent wqiu-hou
enterpV1; status; 1.3.6.1.4.1.1824 6 1;	0; 1.3.6.1.4.1.1824 6 2;	2
enterpV2; status; 1.3.6.1.4.1.1824.0.1;	0; 1.3.6.1.4.1.1824.0.2;	2

The entries in the file tell the plug-in how a system metric is mapped to one or multiple traps. For example, if a SNMP trap Collection Node is created with "localhost" in the agent IP field, the following parameters are discovered in the landscape:

  • linkStatusV1
  • linkStatusV2
  • enterpV1
  • enterpV2
  • statusV1
  • numericV1
  • numericV2

If the agent IP in the Collection Node cannot be matched in the snmp.conf file, the landscape for this Collection Node will be empty. The snmp.conf file can be updated while the Collection Point is running.

The SNMPv1 trap and SNMPv2c trap are different in terms of trap identification. To uniquely identify a trap, a TrapID is defined as:

For SNMPv1: 

TrapID = EnterpriseID[space]GenericTrapNumber[space] SpecificTrapNumber
Example: 1.3.6.1.4.1.1824 5 0

For SNMPv2c: 

TrapID = SNMPTrapOID
Example: 1.3.6.1.4.1.1824.1.0.0.1

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