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Home > Success Center > Network Performance Monitor (NPM) > Polling methods used by Orion

Polling methods used by Orion

Updated March 11th, 2016

Overview

This article discusses the following kinds of polling methods to collect performance information from monitored devices:

  • Internet Control Message Protocol (ICMP)
  • Simple Network Management Protocol (SNMP)
  • Windows Management Instrumentation (WMI)
  • Agents

Environment

All Orion Platform products

Detail​

Internet Control Message Protocol (ICMP)

NPM uses the Internet Control Message Protocol (ICMP) to poll for status using ping and echo requests of managed devices.

  • When NPM polls a managed device using ICMP, if the device is operationally up, it returns a response time and record of any dropped packets. This information is used by NPM to monitor status and measure average response time and packet loss percentage for managed devices.
  • Note: NPM only uses ICMP to poll devices for status, average response time, and packet loss percentage. Other information displayed in the Orion Web Console is obtained using SNMP requests.

Simple Network Management Protocol (SNMP)

For most network monitoring and management tasks, NPM uses the Simple Network Management Protocol (SNMP).

  • SNMP-enabled network devices, including routers, switches, and PCs, host SNMP agents that maintain a virtual database of system status and performance information that is tied to specific Object Identifiers (OIDs).
  • This virtual database is referred to as a Management Information Base (MIB), and NPM uses MIB OIDs as references to retrieve specific data about a selected, SNMP-enabled, managed device.
  • Access to MIB data may be secured either with SNMP Community Strings, as provided with SNMPv1 and SNMPv2c, or with optional SNMP credentials, as provided with SNMPv3.


Notes:

  • To properly monitor devices on your network, enable SNMP on all devices that are capable of SNMP communications. The steps to enable SNMP differ by device, so you may need to consult the documentation provided by your device vendor.
  • If SNMPv2c is enabled on a device you want NPM to monitor, by default, NPM will attempt to use SNMPv2c to poll the device for performance information. If you only want NPM to poll using SNMPv1, you must disable SNMPv2c on the device to be polled.


For more information about MIBs, see

For more information about SNMP credentials, see

Windows Management Instrumentation (WMI)

Windows Management Instrumentation (WMI) is a proprietary technology used to poll performance and management information from Windows-based network devices, applications, and components.

  • When used as an alternative to SNMP, WMI can provide much of the same monitoring and management data currently available with SNMP based polling with the addition of Windows specific communications and security features.
  • Note: Due to specific characteristics of WMI polling requests, polling a single WMI enabled object uses approximately five times the resources required to poll the same or similar object with SNMP on the same polling frequency.
  • For more information about WMI, see the Microsoft article, About WMI. (© 2017 Microsoft, available at https://msdn.microsoft.com, obtained on May 8th, 2017.)

Agents

An agent is a software that provides a communication channel between the Orion server and a Windows computer. Agents are used to provide packet-level traffic information about key devices and applications that you specify.

This can be beneficial in the following situations:

  • Allows for polling host and applications behind firewall NAT or proxies
  • Polling node and applications across multiple discrete networks that have overlapping IP address space
  • Allows for secure encrypted polling over a single port
  • Support for low bandwidth, high latency connections
  • Polling nodes across domains where no domain trusts have been established
  • Full end-to-end encryption between the monitored host and the Orion poller 

 

Note: While changing polling method from SNMP to WMI make sure to List Resources in order to select intended objects/properties for polling.

 

Disclaimer: Please note, any content posted herein is provided as a suggestion or recommendation to you for your internal use. This is not part of the SolarWinds software or documentation that you purchased from SolarWinds, and the information set forth herein may come from third parties. Your organization should internally review and assess to what extent, if any, such custom scripts or recommendations will be incorporated into your environment.  You elect to use third party content at your own risk, and you will be solely responsible for the incorporation of the same, if any.

Last modified
15:13, 8 May 2017

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