Active Vs. Passive Monitoring: Which is Best for Your Network?

Monitoring networks is such a critical function for IT departments, but doing it effectively is a big challenge: Spearline—which independently monitors toll-free, toll and premium-rate phone numbers—conducted a study that found 1 in 25 calls across the globe fail to connect, despite the heavy investments carriers make in network monitoring tools.

This shows how a company’s day-to-day operations depend so heavily on network performance. Customers, employees, senior executives and business partners all need fast access to applications, services and data. If any bottlenecks or security breaches occur, they must be identified and mitigated immediately.

Otherwise, the business suffers and end-users start inundating the help desk!

By leveraging one of the leading monitoring solutions, network admins can adjust segment loads, identify transmission losses, and check resource parameters such as power consumption. Other key functions provided by network monitoring tools include uptime/downtime indicators that send alerts via email and text along with the ability to customize the performance thresholds at which the alerts are generated. SNMP integration, automatic topology discovery, and network mapping are other common functions.

Two of the most common methods of performance monitoring are active and passive monitoring. Some monitors specialize in one or the other, while some vendors provide monitors with the ability to do both. To understand the differences between active and passive, and which one is best for you, this article provides a quick rundown of both methodologies.

Active Monitoring: A Proactive, Predictive Approach

Active monitoring takes a proactive approach to network troubleshooting by highlighting potential problems before they impact end-users. The technology simulates end-user behavior rather than examining actual users and data. In this sense, active monitoring helps network administrators predict how real users will behave on a network. The emulation can occur in real-time and at intervals set by the network admin.

The major benefit of active monitoring is complete visibility into the network and the ability to instantly eliminate blind spots. You can also measure the impact of newly-integrated hardware devices on network performance and target analysis to focus on specific network segments that act up.

Since active monitoring is based on predictive data, it doesn’t always provide an accurate accounting of network performance. It works best when analyzing a specific metric, but it cannot cover every aspect of your network all at once. It can also drain your network resources because of the constant data analysis that occurs.

Passive Monitoring: Real, Holistic Data

Conversely, passive monitoring gathers actual user data and analyzes it over specific time periods, pulling from specific network connections. The technology collects and generates larger amounts of performance data than active monitoring because it doesn’t need to run as often. The data also provides a more holistic view of a network’s performance and can cover a wide spectrum of metrics.

Since passive monitoring gathers actual user data, network admins are informed of issues that directly impact end-users. Rather than making changes based on predictions, admins receive alerts on issues that need to be addressed immediately.

Compared to active monitoring, passive monitoring generates less strain on network resources because the interval between testing is greater. However, passive monitors typically analyze flow to-and-from a specific device, thus requiring specialized hardware.

Best to Use Both

While some technology vendors only provide either active or passive monitoring, there’s no need to make a choice. You can use both!

Each technology is important. Active monitors generate predictive data to warn you of potential network issues and maintain visibility across the entire network. Complementing this, passive monitors show you the end-user perspective by using real performance data.

Using a combination of both is the best way to monitor and modify your network’s performance. You can generate refined data that gives you a complete picture of your network and helps you determine what needs to be done to keep all your end-user audiences happy.

Protection for Your Online Brand Too

In addition to playing a key role in making sure your internal networks perform optimally, network monitoring is also critical for protecting your online presence and your brand—helping you stay connected to your external users, including customers. In addition to making sure customers can access your services efficiently and that your applications experience minimal downtime, you can also protect customers against cyberattacks.

Network monitoring helps you take on this challenge by enabling you to pinpoint where network performance needs to improve and how to generate optimal performance from your compute resources and process flows. You can also identify failing hardware components and network nodes, and fix broken links that might degrade network efficiency.

If you are looking for a network monitoring solution, consider WhatsUp® Gold. The solution covers you from the network edge to the cloud so you can see developing issues before users report them. You can also troubleshoot fast from an interactive network topology map that shows connectivity and dependencies. To check out WhatsUp Gold, you can download a free trial.