Network traffic monitoring is traditionally based on SNMP queries. This protocol generates statistics on the transmission of data across one or more network interfaces.

While network device queries still run through SNMP, using Microsoft Hyper-V monitoring requires the adoption of other approaches. One of the reasons is the network connection configuration itself: for example, many physical network interfaces of a Hyper-V device belong to a logical interface that can also distribute network traffic to multiple network devices, such as multiple switches. Another reason for using an alternative approach is that Microsoft has abandoned the maintenance of SNMP services on their operating systems.

Consider a physical network with the following configuration: a physical Hyper-V host has two active physical network connections that are connected to the network via two switches.

Esempio di cablaggio di una rete fisica

Example of a physical network

This architecture is expanded from a logical level (inside the Microsoft Hyper-V infrastructure) to an additional layer: the Hyper-V virtual network adapter. This forms the interface for the Hyper-V infrastructure to transfer data packets to the network. An example of this infrastructure might be similar to the example below.

Esempio di cablaggio di rete con interfaccia per l'infrastruttura Hyper-V

Example of a Hyper-V infrastructure network

Under this setup, it is not possible to calculate overall transfer statistics, for either the switch or the server, considering the physical interfaces. For instance, if you aggregate all inbound traffic that arrives at “Core_Switch 1”, you will get an overview of the entire Hyper-V infrastructure. However, you can’t determine the traffic generated by a single Hyper-V host, since traffic is distributed across multiple switches. That’s why it’s necessary to take logical interfaces (such as ‘VM1’ above) into account when measuring network traffic.

To achieve this goal, we used PowerShell commands to call a Hyper-V script via NSClient ++. This script is based on the “Get-NetAdapter” command and provides statistics for transferring all logical network interfaces through “Get-NetAdapterStatistics”. These statistics consist of byte counts and must be calculated in a subsequent step based on the intervals that have elapsed since the last call.

The result of the calculation is formatted according to Nagios standard so that they can be later displayed in NetEye.

neteye_perfData

Charts are displayed with PNP4Nagios and also in the latest version of NetEye in Grafana based on the data collected in InfluxDB.

neteye_perfGraph

If you would like a copy of the PowerShell script and a brief NSClient ++ (version 0.4.x) configuration guide, please download the following zip file: netAdapterStatistics

Patrick Zambelli

Patrick Zambelli

Product Manager at Würth Phoenix
After my graduation in Applied Computer Science at the Free University of Bolzano I decided to start my professional career outside the province. With a bit of good timing and good luck I went into the booming IT-Dept. of Geox in the shoe district of Montebelluna, where I realized how a big IT infrastructure has to grow and adapt to quickly changing requirements. During this experience I had also the nice possibility to travel the world, while setting up the various production and retail areas of this company. Arrived at Würth Phoenix I started developing on our monitoring solution NetEye. Today, in my position as Product Manager, I aim to continuously improve our solutions and to adapt them to actual market requirements.
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