May 05, 2023

Article at Virima

Active vs Passive Scanning in IT Environments


The most common use of network scanning is to detect the assets on a network, such as computers and printers. Network scanning can be automated and classified as active or passive. Active scanning sends traffic onto the network while passive scanning merely listens for traffic coming from devices on the network.

Scanning has greatly evolved over the years. Today’s data centers are becoming more complex and dynamic, which requires proactive solutions to ensure security and compliance. Many companies rely on periodic scanning, which can never be fully effective. However, passive mapping allows you to generate more accurate and reliable results.

But what works best for your organization? Let’s find out.

Read: Why IT discovery is critical for vulnerability management?

Passive and active asset discovery

Passive scanning is what happens when a vulnerability scanner runs on a network and detects assets. It’s the most common type of asset discovery, but it has some limitations.

Active scanning is when you tell the scanner to scan a specific IP range. This can be more effective than passive scanning because it allows you to specifically target certain devices or areas in your environment that may have been missed during passive discovery. 

However, active scanning can also cause more disruptions if done incorrectly or without proper planning beforehand – especially if there are lots of hosts being scanned at once.

What is passive asset discovery?

Passive asset discovery is a technique that uses existing network traffic to detect the presence of assets on the network. Passive scanning is less intrusive than active scanning, as it does not generate any additional traffic on the network. Passive scanning is often used for asset discovery because it provides an accurate representation of what’s actually present in your environment.

Passive scanning can be performed using either promiscuous mode or directed mode sniffers (packet analyzers). Promiscuous mode sniffers capture all packets sent over Ethernet networks, whereas directed mode sniffers only capture packets sent to or from specific MAC addresses within range of their physical interface.

Read: Manage cyber risks with cybersecurity asset management

What is active asset discovery?

Also known as standard asset discovery, active asset discovery is a method of monitoring IT assets by examining their traffic and examining the IT environment. Using this method, it is possible to determine different types of devices using an IP address (such as an operating system or vulnerability).

Active discovery can be used through ping-and-response, meaning that a device pings another device, which responds with its information. This process can be repeated until all devices have been discovered. Another method of active discovery is by attempting to log into devices to pull out a complete inventory of connected applications.

Active scanning vs. passive scanning

Active scanning is the most effective way to find assets and vulnerabilities on your network. Active scanning will send out packets to each IP address on your network, so it’s more likely that you’ll find everything that needs to be scanned.

Passive scanning is more likely to find more assets to be scanned. Passive scanning is the most common method for identifying devices on your network, but it may take longer than active scanning because it relies on other devices sending packets out into the Internet and waiting for responses.

Let us take a close look into the difference between active and passive scanning

Stay ahead of cyber threats with Virima

Mastering the art of active versus passive scanning is a must for every IT security team. Avoid “scan storms” and false positives with Virima’s intelligent design that won’t flood the network with unnecessary traffic or impact device performance. Scan results show the successes, failures, and reasons for failure.

If you’re looking for a way to quickly and easily discover all the IP-based assets on your network, Virima Discovery is the tool for you. It’s simple to use and easy to configure, so you can get started right away.

Unlike other tools that require agent deployment or complex setup processes, Virima Discovery lets you scan your network by simply selecting subnets and ranges. You’ll be able to see all of your assets in just minutes!

Virima Discovery is designed to work when your organization needs it most.

Hundreds of out-of-the-box, extendable IT asset discovery probes and sensors allow you to get the job done quickly, reliably, and with minimal disruption. Custom probe generators allow you to create new probes for your environment in just a few clicks! Automated with set-and-forget scheduling ensures that your scans are only running when they are most effective: during off hours or during low demand periods. There’s more to Virima Discovery than meets the eye! Find out all about it with a demo.