SNMP Plugin

The SNMP plugin is automatically enabled when you add a new device to SevOne NMS. Simple Network Management Protocol (SNMP) is a key technology to manage networks of any size. You should enable the SNMP plugin for all devices. SNMP enables the collection of basic performance metrics and QoS data. SNMP metadata is vital for the proper operation of flow technology monitoring and other plugins such as IP SLA, NBAR, Process, and Proxy Ping. See the SNMP topic for details.

Devices for which you enable the SNMP plugin can display the following common SNMP indicators on the Device Summary, when available.

CPU Total - Displays the following CPU total data.
- Name
- Idle CPU Time
- Kernel CPU Time
- Nice CPU Time
- System CPU Time
- User CPU Time
- Waiting CPU Time
CPU - Displays the following information for each CPU.
- Name
- CPU Load
Memory - Displays the following memory information.
- Name
- Description
- Available Real Memory
- Available Swap Memory
- Total Free Memory
- Total Used Memory
Disks - Displays the following disk information.
- Name
- Description
- Available Disk Space
- Used Disk Space
- Storage Used
- Used Storage Indicators
- Hard Drive Storage Used
Interfaces - Displays the following information for each interface on the device.
- Interface Name
- Utilization (In Out)

The Cluster Manager > Cluster Settings tab enables you to define cluster wide SNMP settings. After you enable the device to send SNMP data to SevOne NMS, perform the following steps to enable the SNMP plugin for each device from which you want to poll SNMP metrics.

From the navigation bar, click the Devices menu and select Device Manager.
Either add a device with the SNMP plugin or edit a device to define the SNMP plugin.
- Click Add Device to display the New Device page.
- Click to display the Edit Device page.
- Click the plugin drop-down (displays SNMP by default) and select SNMP, if needed.
Select the SNMP Capable check box.
Click the Version drop-down and select an SNMP version. Version 2c is common and includes 64 bit counters and newer MIBs. If you select a version that is not compatible with the device, SevOne NMS tries a lower SNMP version (unless you select the Lock Version check box).
Select the Lock Version check box to use the SNMP version you select in the previous step. This prevents SevOne NMS from trying to determine the proper version if the version you select fails.
In the SNMP Port field, enter the port number on the device for SevOne NMS to poll SNMP data (default - 161).
If you select Version 1 or Version 2c, perform the following steps.
1. In the Read Community String field, enter the read community string SevOne NMS needs to authenticate onto the device if the string is different from what you enter on the Cluster Manager > Cluster Settings tab. Leave blank to use the Cluster Manager entry.
2. In the Write Community String field, enter the read-write community string SevOne NMS needs if the string is different from what you enter on the Cluster Manager > Cluster Settings tab. Leave blank to use the Cluster Manager entry. This is required if you plan to use the Proxy Ping plugin or the IP SLA plugin where SevOne NMS sends SNMP SET commands to the device.
If you select Version 3, perform the following steps.
1. In the Username field, enter the user name SevOne NMS needs to authenticate onto the device.
2. In the Password field, enter the password SevOne NMS needs to authenticate onto the device.
3. Click the Authentication Type drop-down.
  - Select None (usmNoAuthProtocol) to not use an authentication method to send or receive messages.
  - Select MD5 (usmHMACMD5AuthProtocol) to use MD5 authentication protocol for messages.
  - Select SHA (usmHMACSHAAuthProtocol) to use SHA authentication protocol for messages.
4. If you select MD5 or SHA in the previous step, click the Encryption Type drop-down.
  - Select None to not use encryption to send or receive messages.
  - Select AES to use the Advanced Encryption Standard encryption method.
  - Select DES to use the Data Encryption Standard encryption method.
5. If you select AES or DES in the previous step, in the Encryption Key field, enter the localized key the authentication protocol on the device requires to authenticate messages.
6. In the Context Name field, enter the SNMP context name which defines a collection of management information that is accessible to an SNMP entity. Context can be a physical or logical system, a collection of multiple systems, or even a subset of a system.
In the Test OID field, enter the OID to use to verify the SNMP settings (default = .1.3.6.1.2.1.1.1.0 which is the value for sysDescr.0).
In the Query Delay field, enter the number of seconds to wait after each SNMP command or query. The SNMP plugin issues a series of SNMP queries to discover objects on the device. There are some devices that cannot handle the frequency at which SevOne NMS issues these queries. This enables you to adjust the query frequency and supports fractional second entry when your scenario requires faster queries. You should consider this setting based on the number of SNMP objects on the device.

If you set this to 20 seconds for a device with few objects, discovery could take a short time, but if you set this to 20 seconds for a device with hundreds of objects, discovery could take weeks.
In the Query Delay (on Failure) field, enter the number of seconds to wait after a failure of an SNMP command or query. When an SNMP query fails (expected behavior during SNMP discovery) this is the number of second to wait before the SNMP plugin issues the next query.
Click the Test This Device's Saved Settings link to display the SNMP Walk page where you can perform an SNMP walk.
Click the Synchronize Interface Administrative Status drop-down.
- Select Auto to use the setting from the Cluster Manager.
- Select On to disable and hide the administratively down interfaces and to enable and show the administratively up interfaces.
- Select Off to poll all interfaces by default.
Click the Synchronize Interface Operational Status drop-down.
- Select Auto to use the setting from the Cluster Manager.
- Select On to disable and hide the operational down interfaces and to enable and show the operational up interfaces.
- Select Off to poll all interfaces by default.
Click the Strict RFC 2233 Support drop-down.
- Select Auto to use the setting from the Cluster Manager.
- Select No to not use strict RFC 2233 Support.
- Select Yes to have interfaces under 20Mbps not support 64 bit counters when 32 bit counters are also available. Interfaces found to be over 20Mbps do not support 32 bit counters when 64 bit counters are also available. Exercise caution because certain sequences of Strict RFC 2233 Support and Prefer 64 bit Counter can result in data loss.
Click the Prefer 64bit Counters drop-down.
- Select Auto to use the setting from the Cluster Manager.
- Select Allow Both to use both 64 bit and 32 bit counters.
- Select Prefer 64bit to set interfaces found to be under 20Mbps to not support 64 bit counters when 32 bit counters are also available. Interfaces found to be over 20Mbps do not support 32 bit counters when 64 bit counters are also available. Exercise caution because certain sequences of Strict RFC 2233 Support and Prefer 64 bit Counter can result in data loss.
- Select Prefer 32bit to use 32 bit counters.
Select the IP/Interface Correlation check box to walk the ipAdEntAddr-like entries for IP address information. Some SNMP agents do not support this and may have issues with it. Some devices have vast numbers of IP addresses which increases discovery time. This information helps monitor flow technologies, but is not required.
Select the Trap Destination Discovery check box to discover trap destinations for the device. Some SNMP agents do not support this and may have issues with it. Some devices have vast numbers of destinations which increases discovery time.
After the device has been discovered you can click the View Device Trap Destination Associations link to view the trap destinations that are available for the device.
Click the Max PDU Discovery drop-down.
- Select Auto to use the setting from the Cluster Manager.
- Select On to attempt to discover the maximum number of PDUs allowed for the device.
- Select Off to not attempt to find the maximum number of PDUs on the device and to enter the maximum number of PDUs to discover in the Max PDU field.
Click the SNMP Walk Max Repetitions drop-down to choose either Default or Manual. If you choose the Manual option, Max Repetitions field becomes available which allows you to specify the maximum number of iterations over the repeating variables. Max Repetitions must be a positive integer between 1 and 30.
Click Edit Indicator Types to Monitor to display the Indicator Type Map page where you select to enable or disable the SNMP indicator types to poll on the device.

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SNMP Plugin