SNMP Monitor

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The SNMP monitor tests the SNMP enabled devices for performance and fault data.

The following table lists the SNMP monitor files.

Table 1. SNMP monitor summary 

Monitor files

Name or location

Monitor executable

nco_m_snmp

Properties file

$ISHOME/etc/props/snmp.props

Rules file

$ISHOME/etc/rules/snmp.rules

Log file

$ISHOME/log/snmp.log
Guidelines for configuration SNMP monitor

The SNMP monitor acquires data from SNMP enabled devices by sending SNMP GET requests for one or more objects that are contained in a device's MIB. The device then returns the MIB data to the SNMP monitor. The SNMP monitor supports SNMP versions 1, 2c, and 3.

SNMP monitor operation

Properties
Properties options specific to the SNMP monitor are described in the following table.
Table 2. SNMP monitor properties options 

Property name

Property parameter

Description
InvalidBps Value

integer

Specifies an integer value that is substituted for bits per second (Bps) value calculations when only one data point is available.

MibDir

string

Specifies the directory that contains MIB documents that are used by the monitor.

Default: $ISHOME/mibs.

StripQuotes

 
0|1

Strips quote characters from integer data.

0 - disabled

1 - enabled

Rollover Threshold integer The value that a delta must meet or exceed if a rollover happens before a router reset occurs.

Default: 0 (never rollover)
Configuring the SNMP monitor service tests
Use the SNMP monitor configuration parameters to define service tests.
Table 3. SNMP monitor configuration

Field

Description

server

The server to send SNMP GET requests to.

objectgroupname

The text name for the group of OIDs to include in the GET request.

communitystring

The SNMP read/write community string for the SNMP server on the client.

Note: Use a caret character (^) in community names advisedly, see Community names for further information.

description

A text field for providing descriptive information on the element.

port

The port on the server to use.

Default: 161

version

The SNMP version to use:

1 - SNMPv1

2 - SNMPv2c

3 - SNMPv3

Default: 1
securityname† The username for the SNMP session.
authenticationphrase† The authentication password for the user.
privacyphrase† The privacy password for the user.
authenticationprotocol† The protocol to use to authenticate the user:
  • MD5
  • SHA1
  • SHA-224
  • SHA-256
  • SHA-384
  • SHA-512

Default: MD5
privacyprotocol† The protocol to use for encrypting the session.
  • DES
  • AES
  • AES256
  • AES192
  • AES192C
  • AES256C

Default: DES

timeout

The time, in seconds, to wait for the server to respond.

Default: 20

poll

The time, in seconds, between each poll.

Default: 300

retries

The number of times the monitor retries to contact the server before it quits.

Default: 0

failureretests

The number of times to retest before failure is indicated.

Default: 0

retestinterval

The time, in seconds, to wait between each failure retest.

Default: 10

hostnamelookuppreference
Determines which IP version, IPv6, or IPv4, is applied to the supplied host name. Options are:
  • default sets the monitor to use monitor-wide properties settings. This is the default.
  • 4Then6 selects IPv4 and then IPv6. Uses IPv4 addresses if they are available. If no IPv4 addresses are found, IPv6 addresses are used.
  • 6Then4 selects IPv6 and then IPv4. Uses IPv6 addresses if they are available. If no IPv6 addresses are found, IPv4 addresses are used.
  • 4Only selects IPv4 only. Uses IPv4 addresses only. If there are no IPv4 addresses, the poll returns an error.
  • 6Only selects IPv6 only. Uses IPv6 addresses only. If there are no IPv6 addresses, the poll returns an error.
  • 6Or4 selects either IPv4 or IPv6. Uses the first address that is returned from the host name.
† Applicable only to SNMPv3.
Community names

Internet Service Monitoring uses the caret character (^) as an escape character as it sends information to the target device. If a community name contains a carat, you must enter two carats in a row (^^) for the name to be correct at the router. For example, for the community name a$^&b to be correct when sent to the device use a$^^&b.

Service level classifications
Service level classifications define the rules for determining the level of service.

Available service level classification options for the SNMP monitor are:

totalTime
message

In service level classifications.

  • Specify more service level classifications by manually entering the name of the monitor element. The name must match the name that is shown for the element in the Monitor elements section.
  • message can be any message that is forwarded in the $message element to IBM® Application Performance Management server if used in any widget. For a list of possible values, see Status messages.
  • The operand is a string or a positive number.
  • oidName is the name that is assigned to a MIB object in the OID Name field defined in the OID group.
Monitor elements
In addition to the test results common to all elements, the SNMP monitor generates a set of test results that contain data specific to SNMP service tests.

The following table describes the additional elements for the SNMP monitor.

Table 4. SNMP monitor elements 

Element

Description

$community

The SNMP community string for the SNMP server on the client.

$numOids

The number of OIDs used in the query.

$oidGroupName*

(OidGroup)

The name of the OID group. The OID group contains the OIDs that the monitor is polling.

$oidName0 to n*

(OIDNameZero to Nine )

The name of the first to the last MIB object in the OID group. It is indicated by a number when using Netcool/OMNIbus and by alphabetic text (zero to nine) when using IBM Application Performance Management.

$oidNames

The names of each OID separated by a vertical bar ( | ).

$oidReturnValues0 to n*

(snmpResultZero to Nine)

The data that is returned by the SNMP GET command for the first to the last MIB object in the OID group. This is indicated by a number when using Netcool/OMNIbus and by alphabetic text (zero to nine) when using IBM Application Performance Management.

$oidUnit0 to n

The units for the first to the last MIB object in the OID group indicated by a number.

$oidUnits

The units for each OID, separated by a vertical bar character (|).

$port

The port on which the service is monitored.

$snmpVersion*

(SnmpVersion)

Version of SNMP used to send SNMP packets configured in the profile (Version 1, 2c or 3).
Status message
The SNMP monitor provides status messages in the ResultMessage attribute when using IBM Application Performance Management. These messages indicate the result of the test.

The following table describes the SNMP monitor status messages.

Table 5. SNMP monitor status messages

Message

Description

Successful Get

The query of the SNMP agent was successful.

Failed to open snmp sessions

SNMP session - start failed

Unable to initialize an SNMP session.

Error in packet

Unable to create a valid SNMP packet.

Timed out while waiting for response

No response received from the SNMP agent.

Internal Error

This was an internal error in the monitor. For more information, contact IBM Technical Support.

Error Processing OID

There was an error processing one of the OIDs.

ERROR: Too Many OIDs

The monitor is set to request too many OIDs at one time. The maximum is 100.

ERROR: PDU received mismatch with PDU sent

The protocol data unit (PDU) received by the monitor did not match the PDU sent to the server.