Overview

The SNMP Table Event Monitor can monitor one or more items in a dynamically changing SNMP table.

Use Cases

• Monitoring a table of SNMP values that grows dynamically

Monitoring Options

This event monitor provides the following options:

SNMP Version

Select the SNMP version that will be used to collect the inventory data. The best version to use will depend on how your network devices have been configured. Most devices support SNMPv1 but some may require SNMPv2 or SNMPv3.

Community

Enter the SNMP community string that will be used to connect. The community string is equivalent to a password. The default community string for read-only access is "public" so use this value if you are unsure of what community string your devices are configured to use. The community string is only required for SNMPv1 and SNMPv2c connections. SNMPv3 uses different authentication parameters.

Port Number

The standard port number for SNMP requests is 161. If your devices have been configured to use a different port you can specify it here.

Timeout

The timeout tells the event monitor how long to wait for a response. The default value is best for almost all situations but you can increase or decrease it if you choose.

Retries

Since SNMP runs on UDP packet, delivery and response are not guaranteed. For this reason it is good practice to tell the event monitor to retry one or more times if it does not receive a response.

Username (SNMPv3 Only)

Specify the user name that will be used when connecting to the network device. This is a required value for the SNMPv3 protocol.

Context (SNMPv3 Only)

In rare cases a context string is required to establish the SNMPv3 connection. If required by your devices, enter it here. This value is optional.

Security Level (SNMPv3 Only)

SNMPv3 connections can support both authentication and privacy. Authentication means that a valid passphrase must be supplied or the SNMP unit will not accept the connection. Privacy means that the connection to the SNMP device must be encrypted otherwise the device will not accept it. Both are optional. If your devices do not require either, select noAuthNoPriv. If you devices require authentication but not privacy, select authNoPriv. If your devices require both authentication and privacy, select authPriv.

Auth. Protocol Level (SNMPv3 Only)

If authNoPriv or authPriv is selected for the security level, you must specify the authentication protocol for the connection. Supported values are MD5, SHA, SHA-224, SHA-256, SHA-384 and SHA-512. Consult the documentation and configuration of your network devices to determine which protocol they support.

Auth. Passphrase (SNMPv3 Only)

Enter the authentication passphrase that your SNMP devices have been configured to accept. This value is required when authNoPriv or authPriv is selected for the security level.

Privacy Protocol (SNMPv3 Only)

If authPriv is selected for the security level, the privacy protocol must be selected. The supported values are DES and AES.

Priv. Passphrase (SNMPv3 Only)

Enter the privacy passphrase that your SNMP devices have been configured to accept. This value is required when authPriv is selected for the security level.

Alert with [Info/Warning/Error/Critical] if the device cannot be contacted by SNMP

Select this option to get alerts if it can't contact a selected network device. It's usually a good idea to enable this option because your monitoring configuration will likely have other event monitors to warn if systems are down and if a system is down, its inventory data can be refreshed on the next run.

Alert with [Info/Warning/Error/Critical] if the SNMP values are not found

With this option selected the event monitor will alert if any of the specified table items are not found.

Include a table of the result data [before all/after all] event text

Selecting this option will tell the event monitor to include a table showing the values that were detected.

Table Base

Enter the base path of the table you want to monitor. For example, if you want to monitor network interfaces using the ifTEntry table you could use "iso.org.dod.internet.mgmt.mib-2.interfaces.ifTable.ifEntry" for the table base.

Label Index

Enter the name of a table item that will be used as labels for the detected table items. For example, in the ifEntry table, the ifDescr table item contains the description for each interface.

Table Items

Enter one or more table items that will be monitored. For example, you can use ifOperStatus to retrieve and check the operational status for each interface in an ifEntry table. For each table item, you can also choose a comparison type, data type, and thresholds for alerting.

Authentication and Security

For SNMPv1 and SNMPv2c, a community string for the device being monitored is required. For SNMPv3, a username and other SNMPv3 parameters are required.

Protocols

Data Points

This event monitor's data points are based on the table items you choose to monitor. They will appear as data points in the data point chooser.

Sample Output

Tutorial

To view the tutorial for this event monitor, click here.