When you’re evaluating network monitoring software options, most of the comparison you’ll do is apples to apples. Does the software offer manual or automatic network mapping? Does the software require any custom coding or configuration? Can it analyze flows data? All of these questions have straightforward answers.
But things get confusing when you start to compare network monitoring software licensing models. Licensing is different vendor to vendor, making it difficult to truly compare the value of one solution to another.
Knowing which licensing models are out there and how they work is crucial so you understand not only how your initial investments compare, but what investing in a particular solution will look like over time. For instance, as your network grows, how often will you need to buy additional licenses? How much will your total cost of ownership actually be?
The three most common licensing models you’ll see are as follows:
- Per device
- Per interface
- Per sensor
Some vendors only offer one model, while others offer a hybrid of several. Here’s how these common licensing models work and what they mean to your bottom line.
Licensing by device
Per-device (or node) licensing is one of the most common models because it’s the simplest to understand and maintain. Let’s say you have 100 machines in your network that you want to monitor: servers, routers, firewalls, workstations, printers, and more. Device-based licensing means you’ll need 100 licenses; one for each device (physical or virtual) that you plan to monitor.
Per-device licensing means it’s easy to predict costs as your network grows. If you plan to purchase 25 new workstations next year, you’ll need 25 new licenses.
Licensing by interface
Software that is licensed by interface (a.k.a. link or port) means that you need a license for each network interface that you want to monitor. Because devices can have one to many interfaces, it’s harder to estimate how many interfaces you will need to get licenses for. For networks that change frequently, these costs can skyrocket fast.
Licensing by sensor
A sensor is one measurable element of a device that you can monitor, such as memory utilization or CPU load on a machine. For licensing by active sensor (also referred to as measurement or test), if you have five sensors per device and 100 devices, you would be paying for 500 sensors.
The benefit of sensor-based licensing is that it gives network administrators very granular monitoring over the components of their devices. But again, figuring out what your final cost will be at the time of purchase will require inventorying your network.
Plus, unless you have a clear plan of exactly what you want to monitor, you won’t be able to predict your costs accurately. For many network administrators, they just want to get up and running with monitoring devices—they don’t necessarily want the burden of creating a set strategy beforehand to slow them down.
Related Content: How Do Device-Based and Sensor-Based Licensing Compare?
Although vendors usually just offer one licensing model, some vendors may provide hybrid models, basing pricing on whatever element is highest. For example, if you have 100 devices with 1000 interfaces, the pricing would be based on interfaces. Because most devices have one to many interfaces, the pricing will typically end up being interface-based.
What’s best for your network?
Ultimately, it comes down to this: how much work are you willing to do when it comes down to your software licensing? If your network hardly ever changes, interface and sensor-based licensing may not prove too cumbersome. But most networks experience some degree of flux over time. To future-proof your network, selecting network monitoring software with a simple, easy-to-follow licensing model will require less calls to your support team and mean less cash you have to fork over in the long run. Additionally, some vendors require a separate architecture to support license keys. Make sure to ask about this when you’re evaluating costs and ease of deployment, as a built-in license administrator will be easier to manage.
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