What's on your network? It's a simple question, but one that countless security and network management teams struggle to answer because most enterprise networks are dynamic, living things that change at a rapid pace. That change is the key to adapting to a changing business environment — and key to criminals' ability to breach the perimeter and gain access to enterprise assets.
Security teams tend to have a very good idea of what the network looked like on the day it went live. Nevertheless, conversations with consultants (and over drinks at conferences) overflow with complaints and confessions about how those same teams are ignorant of what the network looks like right now. That's a problem. And it becomes a bigger problem when it runs into the reality of the way that criminal hackers work.
Criminal hackers specialize in understanding how a targeted network is configured today. The extent to which they understand every component and interface is the extent to which they can find exploitable vulnerabilities. And those weaknesses are even more vulnerable if the network owner doesn't know they exist.
So one of the first steps in protecting a network is understanding precisely what is there to be protected. There are a number of different commercial products that can help provide an inventory and map of a network. But for many smaller organizations, even lower cost tools can be difficult additions to the security budget. That's why the focus of this article is on free products that provide network visibility and monitoring.
Some of the products on this list are open source and some are not. Several of them may require an investment of time and effort to make up for the lack of a purchase price. Regardless, each of these could be a way for a security team to either get its first solid picture of its current network or augment the view provided by other tools. In either case, visibility is always a good thing.
We're curious; are there free or open source network discovery and monitoring tools that you use? Are there any that you've tried and abandoned? We'd like to hear about your experience — let us know in the comment section, below!
(Image: GoodIdeas VIA Adobe Stock)