How OT Asset Discovery Works: Key Methods and Techniques

Operational technology (OT) refers to the hardware and software systems that monitor, control, and automate industrial equipment, processes, and infrastructure. It’s commonly used in industries like manufacturing, energy, and transportation. 

Therefore, OT asset discovery is the process of identifying, cataloging, and monitoring all operational technology devices and systems within a network to ensure they are visible, secure, and properly managed.

In a car factory, OT has programmable logic controllers (PLCs) orchestrating the assembly line, ensuring each robot welds with precision. In the energy sector, it covers remote terminal units (RTUs) that keep an eye on voltage levels and control the distribution of power. These systems work behind the scenes to make sure everything operates as it should.

Understanding OT is vital because these systems are different from the IT we know in offices. Unlike IT, which deals with data and communication, OT is about the physical world. It’s about controlling machinery and maintaining safety. 

Therefore, OT asset discovery is your first line of defense in securing these environments. You must know every single device plugged into your network, which is like taking inventory of treasures in a safe. Before you can guard them, you must know what and where they are.

Differences between OT asset and IT asset discovery

While both OT and IT asset discovery share the goal of identifying assets, the process and context are quite distinct. In IT asset discovery, the focus is on data centers, office networks, and digital communications. 

IT asset discovery is like managing a busy library where each computer, printer, and server is a book to be cataloged. You focus on software licenses, updates, and data integrity.

In contrast, OT asset discovery focuses on physical assets. It's about identifying devices that control and monitor real-world systems. So on a manufacturing floor or an energy grid, you would find programmable logic controllers (PLCs) that orchestrate machinery, or remote terminal units (RTUs) monitoring power flow. These are not just computers; they are the heartbeat of industrial operations. The stakes are higher, and the environment is more sensitive.

In IT, active scanning is part of the routine. You can perform regular scans to find devices and services without much worry. A printer might simply respond to a ping, or a server could reveal its services with a network query. It's all about keeping an inventory of digital assets that can be easily modified or updated as needed.

But in OT, you tread carefully. Active scanning can be risky. A simple network probe might disrupt a PLC controlling a critical machine, halting production or causing safety issues. It’s like setting off an alarm trying to sneak a peek through a window. Instead, you lean heavily on passive monitoring. You listen to the network traffic, piecing together the presence of devices without making noise.

The categorization of assets also differs. In IT, you might classify by software suite or user department. In OT, it's about the role each device plays in the physical operation. A SCADA system overseeing a reactor plant is a high priority, much like a brain is vital to a body. A temperature sensor might be a toe—important but not as critical.

Relationships between assets are another point of divergence. IT assets interact within a digital ecosystem, sharing data and resources. It’s about network bandwidth and data flow, often in a predictable pattern. 

In OT, interactions are about control and safety. It’s how a PLC talks to a sensor to ensure a machine doesn’t overheat or how a SCADA system monitors an entire plant. Understanding these connections in OT is like mapping out emergency escape routes—crucial for safety and security.

As technology evolves, both OT and IT asset landscapes are in constant flux. In IT, you might find new software updates or devices joining the corporate network. In OT, new machinery or sensors might be added to improve operations. It requires continuous vigilance to keep your maps and defenses up to date. Each has its challenges, but the mission remains the same: to know what you have so you can protect it.

Passive asset discovery techniques

Passive discovery techniques focus on being unobtrusive. In OT asset discovery, you can't afford to be like a bull in a china shop. You must take a more cautious approach by observing the network without altering its natural flow. Think of it as being a fly on the wall, quietly gathering intel.

One approach we often use is listening to the normal broadcast traffic on the network. Imagine strolling through a busy marketplace where everyone’s chatting. You are picking up on valuable snippets of conversation without joining in. 

This might involve capturing syslog messages sent out by devices. For instance, routers and switches might send updates about their status, allowing you to gather details about what's active on the network. Since you are just listening, there's no risk of causing network congestion or interrupting operations. This can be particularly useful in environments where devices are sensitive to any interference.

Passive techniques work best in OT asset discovery because they allow you to piece together a picture of the network without asking each device to identify itself. It’s like being a silent detective, solving a mystery without the suspects knowing they’re being watched. 

However, this doesn’t mean you only work with current data. You can dive into archived logs, much like historians perusing through old newspapers. By examining past syslog data, you can identify devices that might not be actively broadcasting every day. This method helps ensure nothing slips through unnoticed, even those devices that went offline or were temporarily inactive.

Using passive asset discovery methods, you can catalog devices like programmable logic controllers (PLCs) without poking them or pushing buttons. This is crucial because disturbing these devices can halt industrial operations. 

Using passive discovery bridges the gap between IT and OT, allowing you to leverage IT resources and expertise to alert operational tech teams about new devices. It's a smooth symphony where both worlds can share insights without stepping on each other’s toes.

Active discovery techniques in OT asset discovery

Active techniques in OT asset discovery are like using a flashlight in a dark room. You shine a light to reveal what’s there, but you do so carefully. Unlike passive techniques, active discovery involves sending queries or probes to devices. It’s direct, but it carries risks. You must be tactful, ensuring your actions don’t disrupt the delicate balance of OT environments.

One of the more common active techniques is pinging devices. It’s like knocking on a door to see if anyone’s home. When a device responds, you know it’s present and accounted for. This can be useful when you need to confirm the existence of an asset. 

For instance, in a power plant, you might ping remote terminal units (RTUs) to ensure they’re communicating as expected. But you have to tread lightly. Pinging too aggressively could overload devices or even cause them to malfunction.

Another method we use is querying with protocols like SNMP (Simple Network Management Protocol). This is akin to asking a device about its health without stepping inside. SNMP allows you to gather information about device status, configurations, and network performance. It's helpful for identifying things like routers and switches on the network. 

Say you are monitoring a water treatment facility; you might use SNMP queries to check the operational status of pumps and other critical infrastructure. But again, caution is key. You must ensure that your queries don’t interfere with the normal operations of sensitive equipment.

In certain scenarios, we use more extensive scanning techniques, like port scanning. This might remind you to check every window and door of a building to see which ones are open. By scanning for open ports, you gather details about the services running on a device. 

For example, in a smart factory, this could help you identify which machines are running specific control software. However, these scans must be carefully timed and planned. You have to be conscious of the potential impact on operations, so usually, such scans are reserved for maintenance windows or low-activity periods.

Active discovery is a valuable tool, but it requires precision and expertise.  You can uncover devices and services that passive techniques might miss. But each action must be deliberate, with an understanding of the potential repercussions. You must aim to find a balance between gaining critical insights and maintaining the stability of the OT environment.

Combining passive and active methods for comprehensive discovery

Blending both passive and active methods can give you the most comprehensive view of your network. It's akin to using different tools for different tasks. Each has its strengths, and together, they provide a fuller picture. 

In a manufacturing plant, for instance, you start by passively monitoring the network traffic. It’s like eavesdropping on the conversations of programmable logic controllers (PLCs) quietly at work. You pick up on broadcasts and syslog messages, noting the presence of various devices as they communicate. This helps you build an initial map without disturbing the rhythm of the machinery.

However, passive techniques alone might not reveal everything. That's where active methods come into play. Picture a scenario where a device seems inactive—it’s not sending out the usual network noise. Gently pinging it confirms its existence and gathers information it isn’t broadcasting. 

In a smart factory, this could be crucial for ensuring that remote terminal units (RTUs) are still functioning even if they're not actively chatting on the network.

Active methods like SNMP queries give you additional insights. Say you have identified a SCADA system passively. With an SNMP query, you can check its configuration and health status, ensuring it’s operating smoothly. 

It’s like asking a shopkeeper how business is going after observing the hustle and bustle outside their store. This direct interaction helps confirm the details you have gathered passively.

Port scanning can also be useful, but you must approach it with care. For example, in a power plant, you might use it to identify services running on control systems during a scheduled maintenance window. But timing is everything. You must ensure that such active scans don’t upset the balance of operations.

Intertwining passive and active techniques enables you to not only map out devices but also understand how they interact and function. You must create a harmonious balance, ensuring you gather the most information while maintaining the stability and security of your OT environment. Each step taken has a purpose, and every method used complements the other, providing a seamless approach to asset discovery.

How Netmaker Helps with OT Asset Discovery

Netmaker provides a robust solution for enhancing the security and management of operational technology (OT) networks, crucial for asset discovery and protection. By creating secure, flat virtual overlay networks, Netmaker ensures easy and secure communication between devices such as industrial control systems (ICS) and supervisory control and data acquisition (SCADA) systems across diverse locations. Its capability to integrate non-native devices and manage WireGuard configurations automatically adapts as new devices are added or removed, addressing the dynamic nature of OT environments without disrupting operations.

Additionally, Netmaker's features like Egress Gateways and Remote Access Gateways facilitate controlled access to external networks and services, ensuring that OT devices can communicate securely beyond the immediate network. This is particularly beneficial for remote terminal units (RTUs) in energy sectors or programmable logic controllers (PLCs) in manufacturing, as it maintains data flow integrity while mapping out device interactions, enhancing the overall security posture. To get started with Netmaker and take advantage of its capabilities, sign up here.