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
| Feature | Active scanning | Passive scanning |
| Security vulnerabilities | Active scanning is often considered more effective than passive scanning, as it can detect more vulnerabilities. However, it requires users to open firewalls and provide credentials for accessing the server. Sometimes it needs an internet connection which can lead to data leak. | Passive scanning can be used to test the security of your systems and applications without impacting their performance. It can also help you find out if an application is vulnerable before performing a penetration test that might have negative consequences for your business operations. This kind of testing helps you identify vulnerabilities before they are exploited by attackers and gives you time to fix them before they are discovered by those who may use them maliciously. |
| Deployment | Active scanning is not the best option in IT environments. It requires user credentials and firewall permissions, which is time consuming and difficult to manage in big environments. In addition, if you have multiple active directory instances, the process might not work properly. | Passive scanning allows for fully automated deployment and configuration in as little as an hour. This method can be used to set up environments for both new employees and new projects. |
| Resource use | Active scanning can impact your servers in a negative way by causing significant network overhead and by allowing the scanner to access your most sensitive data. | Passive scanning is a valuable security tool that can be used to gain intelligence about the state of your systems without impacting them in any way. A passive scan does not require the server to be up or active, and it does not require an agent to be installed on the system being scanned. This means that passive scanning provides a more accurate picture of what’s going on with your systems than active scanning does. |
| Scalability | Active scanning can be incredibly powerful and effective, but it’s not necessarily very scalable. The reason is that the process involves asking each user to open their firewall and provide credentials in order to scan the entire network. This means that if you have a large number of users, it may take time for all of them to complete the process. | Passive scanning is a method of monitoring your network that does not require any active participation from the monitored devices. This means there’s no need to install software on the computers being scanned, which makes it easy to scale from a single server to a large data center. |
| Accuracy | Active scanning lets you know when new devices have been connected, or when connections have been blocked. When you’re using active scanning, you can see all of the connections at once and know exactly what’s happening on your network. However, active scanning can miss areas of your network if the firewall is blocking connections. | Passive scanning is a great way to get a complete, real-time picture of your IT environment. It can discover all applications, their dependencies, and how they interact with one another. This means that there are no blind spots when it comes to understanding how your apps work together. |
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.
