ManageEngine NetFlow Analyzer

NetFlow Analyzer is a flow-based network traffic monitoring tool, and the distinction from general network monitoring is worth being precise about. Device monitoring tells you a link is saturated. Flow analysis tells you what is saturating it and who is responsible. The vendor states the purpose exactly that way: collecting, analysing and reporting on what your network bandwidth is being used for and by whom. When a network slows down, that second question is the one that leads to a fix.

It works by leveraging flow technologies rather than packet capture, which is what makes it viable continuously across an entire network. Full packet capture at every point is impractical at scale, whereas flow records are exported by the network equipment already installed, giving real-time visibility into bandwidth performance without additional capture infrastructure.

The scale claimed is substantial: the vendor reports optimising thousands of networks worldwide and monitoring over a million interfaces. Beyond bandwidth monitoring, it performs network forensics, network traffic analysis and network flow monitoring. Forensics is the security-adjacent application, since flow records answer questions about historical traffic that would otherwise be unanswerable after an incident, such as which internal host communicated with a suspect address and when.

The current version is v12.8, and it is available to download with a free trial. Positioning it alongside a device monitoring tool such as OpManager is the common pattern: one tells you something is wrong, the other tells you what traffic is causing it, and the two together cover diagnosis rather than only detection.