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In Frame 4, the Manager sets the value of a Protools private MIB object, called etherUtilization, to a threshold that is acceptable for the current network conditions. The Probe issues a confirmation in Frame 6. In Frames 11–18, the Manager initializes values in the eventTable, which creates a row entry that is indexed by a random number chosen by the Manager (31860). Note that in Frame 15 (Trace 7.11b), values of four of the objects from the eventTable {1.3.6.1.2.1.16.9.1} are specified:


Object OID Value
eventDescription {rmon 9.1.1.2 } % Network usage
eventType {rmon 9.1.1.3 } 4
eventCommunity {rmon 9.1.1.4 } public
eventOwner {rmon 9.1.1.6 } FM/X (XXX.YYY.135.195) :
PID 3632 ID 0x008a0310

The eventDescription object provides a textual description that describes the event (% Network usage). The eventType object defines the type of notification that the probe will make as a result of this event. The RMON MIB, RFC 1757, defines Type = 4 as a “log-and-trap” notification. The eventCommunity object defines the community where the SNMP trap will be sent. The eventOwner object defines the entity that configured this entry. In this case, it is Network General’s Foundation Manager for UNIX product, an RMON console, with the IP address specified above. The PID value is a process identification assigned by the Manager.

Frame 16 is a GetResponse from the Probe to the Manager to confirm the parameters that were set. In Frame 17, the Manager issues another SetRequest, this time for the eventStatus object {1.3.6.1.2.1.16.9.1.1.7} with Value = 1, which validates this table entry. The Probe sends a confirming GetResponse in Frame 18.

Trace 7.11b. RMON eventTable initialization

  Sniffer Network Analyzer data from 21-Feb at 16:47:08, file TRAP.ENC, Page 1
  --------------------------------- Frame 15  ---------------------------------
  SNMP: ----- Simple Network Management Protocol (Version 1) -----
  SNMP:
  SNMP: Version = 0
  SNMP: Community = public
  SNMP: Command = Set request
  SNMP: Request ID = 918004690
  SNMP: Error status = 0 (No error)
  SNMP: Error index = 0
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.2.31860}
  (rmon.9.1.1.2.31860)
  SNMP: Value  = % Network usage
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.3.31860}
  (rmon.9.1.1.3.31860)
  SNMP: Value  = 4
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.4.31860}
  (rmon.9.1.1.4.31860)
  SNMP: Value  = public
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.6.31860}
  (rmon.9.1.1.6.31860)
  SNMP: Value  = FM/X (XXX.YYY.135.195) : PID 3632 ID 0x008a0310
  SNMP:
  --------------------------------- Frame 16 ---------------------------------
  SNMP: ----- Simple Network Management Protocol (Version 1) -----
  SNMP:
  SNMP: Version = 0
  SNMP: Community = public
  SNMP: Command = Get response
  SNMP: Request ID = 918004690
  SNMP: Error status = 0 (No error)
  SNMP: Error index = 0
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.2.31860}
  (rmon.9.1.1.2.31860)
  SNMP: Value  = % Network usage
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.3.31860}
  (rmon.9.1.1.3.31860)
  SNMP: Value  = 4
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.4.31860}
  (rmon.9.1.1.4.31860)
  SNMP: Value  = public
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.6.31860}
  (rmon.9.1.1.6.31860)
  SNMP: Value  = FM/X (XXX.YYY.135.195) : PID 3632 ID 0x008a0310
  SNMP:
  --------------------------------- Frame 17 ---------------------------------
  SNMP: ----- Simple Network Management Protocol (Version 1) -----
  SNMP:
  SNMP: Version = 0
  SNMP: Community = public
  SNMP: Command = Set request
  SNMP: Request ID = 918004691
  SNMP: Error status = 0 (No error)
  SNMP: Error index = 0
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.7.31860}
  (rmon.9.1.1.7.31860)
  SNMP: Value  = 1
  SNMP:
  -------------------------------- Frame 18 --------------------------------
  SNMP: ----- Simple Network Management Protocol (Version 1) -----
  SNMP:
  SNMP: Version = 0
  SNMP: Community = public
  SNMP: Command = Get response
  SNMP: Request ID = 918004691
  SNMP: Error status = 0 (No error)
  SNMP: Error index = 0
  SNMP:
  SNMP: Object = {1.3.6.1.2.1.16.9.1.1.7.31860} (rmon.9.1.1.7.31860)
  SNMP: Value  = 1
  SNMP:

Reviewing Frames 19–24 in Trace 7.11a, the Manager initializes the alarmTable {1.3.6.1.2.1.16.3.1}. Note that in Frame 19, the Manager sets the alarmStatus object to a Value = 2 (createRequest, per RFC 1757), and selects a random number for an index for this table entry (29148). Other values of the alarmStatus table are set in Frame 21 (Trace 7.11c), including:

Object OID Value

alarmInterval {rmon 3.1.1.2} 5
alarmVariable {rmon 3.1.1.3} {1.3.6.1.4.1.209.2.2.1.2.1}
alarmSampleType {rmon 3.1.1.4} 1
alarmRisingThreshold {rmon 3.1.1.7} 1
alarmFallingThreshold {rmon 3.1.1.8} 1
alarmFallingEventIndex {rmon 3.1.1.10} 0
alarmRisingEventIndex {rmon 3.1.1.9} 31860
alarmOwner {rmon 3.1.1.11} FM/X (XXX.YYY.135.195) :
PID 3632 ID 0x008a0310


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