OT environments usually stretch over hundreds of networks – each varying in criticality to whatever industrial processes they’re a part of. But it isn’t easy to converse about OT security if you don’t know which specific OT network you’re talking about. A comprehensive knowledge of one’s network infrastructure is essential for safeguarding.
What is an OT network inventory?
An OT network inventory organizes information about the networks and devices within an OT environment. It details device types, network associations, IP addresses, physical locations, and connectivity information. In OT environments, where the number of networks can easily exceed hundreds within a single site, maintaining an up-to-date network inventory is not just beneficial—it is necessary.
The importance of OT network inventory in OT security
Without a network inventory, any attempt to secure an OT environment is fundamentally flawed. Understanding which networks a device is connected to is the first step in protecting it, and this knowledge is crucial for several reasons.
To understand the vulnerabilities impacting an OT environment, you must understand each device’s network context. Knowing which network a device is on helps identify potential vulnerabilities, understand the network neighborhood, and recognize routing capabilities or risks.
Most OT threat detection tools fall short when it comes to network inventory. They often lack the ability to actively discover networks, which prevents them from providing a complete picture of network associations. This fact makes them less effective in detecting threats and leaves blind spots in your security strategy.
OT network inventories provide the necessary context for devising effective mitigation strategies. Knowing the network associations of devices is needed to implement appropriate network segmentation, which is a key strategy in preventing the spread of threats.
Passive network discovery limitations
Many OT security tools rely on passive discovery methods, which monitor network traffic to identify devices and their connections. This method is limited.
Incomplete Network Visibility: Passive discovery cannot identify networks that a device might be a part of if it isn’t actively communicating over that network during observation. This results in an incomplete picture of the network environment.
Lack of Context: Passive methods might expose IP addresses and some network traffic, but they do not provide detailed network context. That includes VLAN IDs, network masks, and the physical layer details, all crucial for comprehensive security.
Ineffectiveness in OT Environments: OT environments often have multiple private networks, and without active discovery, it’s challenging to determine which network a device belongs to. This lack of clarity hinders the ability to respond to threats accurately.
The case for active network discovery
Active network discovery, as implemented in OTBase, overcomes the limitations of passive discovery by directly interacting with devices to solicit detailed network information. This approach provides several advantages:
- Comprehensive Network Context: It’s more detailed than passive discovery. Active discovery identifies the devices and networks they are associated with, including network addresses, netmasks, and VLAN IDs.
- Automatic Network Topology Mapping: Network topology diagrams can be automatically generated with active discovery, showing physical and logical network layers. This visualization is invaluable for engineers and security professionals, providing a clear overview of the network structure.
- Identification of New Devices: Active discovery can quickly identify new devices added to the network, ensuring your inventory remains current. This capability is critical for maintaining security, as any unmonitored device could be vulnerable.
- Efficient Resource Allocation: Active discovery allows for better planning and resource allocation by providing a detailed OT network inventory. Knowing the exact number of devices and their network connections helps optimize network performance and security measures.
Debunking myths about active discovery
A common concern with active network discovery is the potential impact on network performance and device stability. However, this concern is unfounded mainly when using a well-designed tool like OTBase:
Minimal Traffic Impact: Active discovery in OTBase is designed to be non-intrusive, using legitimate industrial protocols to communicate with devices. This approach minimizes the generated network traffic, making it safe even in sensitive OT environments.
Safe for OT Devices: Unlike traditional vulnerability scanners that can overwhelm devices with traffic, OTBase’s active discovery is tailored for OT environments. It collects necessary metadata without causing disruptions, ensuring that devices operate smoothly.
Proven Reliability: Many OTbase customers run the discovery process with default settings without encountering issues. Its effectiveness in safely gathering detailed network information has been demonstrated across various industrial settings.
A comprehensive OT network inventory is indispensable
In today’s complex OT environments, where the number of networks and devices can be overwhelming, a comprehensive network inventory is not just a luxury—it is a necessity. Active network discovery provides the depth and accuracy needed to build an OT vulnerability management strategy, ensuring that every device and network is accounted for and protected.
Want to know more? Download the OTbase OT Vulnerability Management Handbook.