---
title: "What is NetMirror"
canonical: "https://thoughtdata.refined.site/space/TUD/55480993/What%20is%20NetMirror"
format: markdown
---
ThoughtData NetMirror is a software agent purpose built for virtual environments. In many virtual environments including private or public cloud there is no direct way to access network traffic from the VMs/computing nodes for monitoring. To over come visibility challenges ThoughtData provides a agent software which can be installed on your critical virtual application servers/VMs/computing nodes.

NetMirror software captures bi-directional network traffic from one or more vNICs of your critical application server VMs and streams it to an external Netsense VM. NetMirror software uses very less resources on your VMs and uses very high compression methods to stream the captured network traffic to external Netsense sensor for monitoring. All packet processing is done externally in Netsense and NetMirror only capture, compresses and streams traffic to Netsense sensor. One Netsense sensor can receive network traffic streams from multiple NetMirrors. The external Netsense sensor VM need not be in same hypervisor as the application server VM on which you are installing NetMirror agent.

NetMirror software is more sophisticated than traditional Traffic Mirroring/Port Spanning/promiscuous modes. In  these methods traffic is captured and sent as is without any compression to minimize impact on the bandwidth used for traffic mirroring. NetMirror software runs as a layer 3 process and does not interfere with any application processes running on the application server VM/computing instance on which it is installed.   

Optionally, you can create a separate monitoring VPC network in your private or public cloud and associate a additional traffic streaming vNIC on your critical application servers where NetMirror runs, if you have any concerns about bandwidth overhead of traffic streaming. This method completely removes your concerns about bandwidth usage of traffic streams on your production VPC subnets where your customers use the application services.

NetMirror software is bundled along with Netsense software and the installation package for NetMirror is same as Netsense. However configuration and starting NetMirror process are different.

ThoughtData does not charge additional cost for NetMirror software and NetMirror software is available with your Netsense sensor for you to use wherever you deem fit in your environment.

In some public cloud environments like Azure, Oracle cloud etc NetMirror is the only method and viable option to obtain traffic level visibility into critical application server VMs,

Related Topics

[Installing NetMirror](https://thoughtdata.atlassian.net/wiki/spaces/TUD/pages/55643201/Installing+NetMirror)

[Configuring NetMirror](https://thoughtdata.atlassian.net/wiki/spaces/TUD/pages/55186113/Configuring+NetMirror)

[Setting up your Netsense sensor to receive traffic streams from NetMirrors](https://thoughtdata.atlassian.net/wiki/spaces/TUD/pages/55480987/Configuring+NetSense+for+NetMirror)