Decoding OT Micro-segmentation

Decoding OT Micro-segmentation

Increase security and value in industrial environments with OT micro-segmentation.


As cyber threats to industrial environments increase, it is crucial to have strong security measures. However, implementing these measures can be challenging due to limited resources. One effective approach at the network level is OT micro - segmentation.

But what is OT micro - segmentation and how does it protect industrial environments while being cost-effective? In this blog post, we will answer these questions and provide a detailed guide for CISOs, OT, and IT managers.

Understanding OT Micro - segmentation

OT micro - segmentation, as emphasized by the National Institute of Standards and Technology (NIST) and Gartner , serves as a strategic method to partition industrial network environments. NIST underlines that micro - segmentation is an extremely efficient approach to control and reduce the attack surface of an organization moving away from the traditional flat network architecture.

This micro segmentation approach significantly curtails the potential security risks of a cyberattack and facilitates more rapid incident response and remediation. Micro - segmentation creates a scenario where, even in the event of a network breach, an intruder's access is severely restricted, thereby limiting the extent of potential damage. It helps control network access, allowing only approved devices, apps, and processes into certain areas. This method improves security in IT systems and reduces unnecessary access in industrial settings.


To appreciate the efficacy of micro-segmentation, consider this perspective: In its absence, a single compromised device within your network – be it a surveillance camera, air conditioning system, printer, or Programmable Logic Controller (PLC) – could potentially grant a hacker access to your entire industrial framework. However, with micro-segmentation implemented, the same compromised device is restricted to its specific network segment, dramatically minimizing the possible extent of damage.

5 benefits of implementing OT micro-segmentation in Industrial Environments

OT micro-segmentation allows for an enhanced security strategy in industrial environments by introducing a more controlled and segmented network structure. This strategic approach brings several key benefits to the forefront:

1 - Comprehensive Asset Visibility :

Micro-segmentation provides a detailed and precise view of groups of assets. By mapping assets to corresponding micro-segments (aka zones and conduits) operators and IT teams are not overwhelmed with excessive information. Instead of seeing everything and nothing at the same-time, micro-segmentation provides a clear view of what matters for this particular procedures or business flow.

2 - Granular Access Control :

The ability to define access rules for each micro-segment means that access to network resources can be tightly controlled, offering granular control over who or what can communicate within the network. This granularity allows for specific permissions and restrictions to be set for different user groups or device types. For example, in a power plant, certain employees can access control systems related to the grid, while others are limited to administrative segments, preventing unauthorized access to critical controls.

3 - Limited Blast Radius in Event of Cyber Attacks :

By segmenting the network into smaller zones, micro-segmentation effectively contains lateral movement and therefore limits the spread of cyber threats. Controlling the flow of network traffic - both north-south and east-west - within the network ensures that, in the event of an attack, the impact / movement of threats is confined to a smaller area. This significantly reduces the overall risk to the industrial environment by preventing the widespread dissemination of a cyberattack across network traffic paths.

4 - Faster Response to Security Incidents :

Operators can quickly comprehend and assess the security status of each micro-segment. Knowing that a specific production line is touched allow operators to quickly assess the potential blast-radius and to define a procedure to contain issues. Fast and efficient responses are crucial in maintaining operational continuity in industrial settings. If we take the example of a water treatment facility, if a sensor anomaly is detected in the filtration system segment, operators can swiftly isolate that segment, that asset and address the issue, minimizing disruption.

5 - Improved Compliance with Standards :

Implementing industrial micro-segmentation aids in complying with various industry standards and frameworks, such as NIST SP 800 series and IEC 62443 . These standards emphasize the importance of network segmentation and access control in securing industrial control systems. By adhering to these guidelines, organizations can ensure a higher level of security and operational reliability.

In summary, OT micro-segmentation is not just a defensive tactic against cyber threats but also a strategic approach to optimize network management, enhance OT regulatory compliance , and safeguard critical industrial processes.

Implementing Micro-segmentation with agility

Implementing micro-segmentation in a small manufacturing environment, following NIST guidelines, involves a detailed and collaborative approach:

1 - Identify List of Assets :

The process begins with cataloging all network assets, including hardware and software components. The IT Manager takes charge of this step. They seek advice from the Operation, Security, and Compliance teams for their expertise and knowledge of regulations.

2 - Conduct OT Security Assessment and Create Security Zones :

Here, the risks associated with each asset are evaluated, and similar-risk assets are grouped into security zones. The Security and Operation teams collaborate with the IT Manager. They also consult with the Compliance team. Their goal is to ensure industry standards are met.

3 - Determine the Risk Level for the Security Zones :

This step involves assigning risk levels to each security zone. Risk levels can use a zero to five scale or the traffic-light protocol. This step requires a thorough understanding of the current network configuration to ensure that the micro-segmentation aligns with the operational requirements and security posture of the organization. The Security and Operation teams collaborate with the IT Manager, consulting with the Compliance team to ensure that the new network configuration meets industry standards and enhances security.

4 - Map Communication Between the Security Zones :

Understanding and documenting data flows between zones is crucial. The IT Manager, who oversees this mapping, works with the Security Team to spot possible risks and inefficiencies in how data moves. This step is critical in identifying and mitigating pathways for unauthorized lateral movement, ensuring that measures are in place to prevent threat actors from navigating from one zone to another undetected. By clearly defining and controlling how communication occurs between zones, organizations can further secure their networks against sophisticated cyber threats.

5 - Determine Security Controls for the Security Zones :

The final step is implementing appropriate security controls for each zone based on the assessed risks. The Security Team, supported by insights from the IT Manager, Operation and guidelines from Compliance, defines specific signals to track.

This method of applying micro-segmentation in industrial networks enables a structured yet adaptable execution. It begins with a small segment and gradually extends, ensuring both adaptability and scalability. This approach, in accordance with NIST guidelines, is applicable across various environments and quickly reduces their risk.

How Trout Software helps implementing micro-segmentation in Industrial environments ?

At Trout Software, we're proud of our robust solution for enhancing cybersecurity in industrial environments . Our approach is centered around:

  • We believe in simplicity. Therefore, our product is designed in a manner that enables Ease of Installation . It is packed in an uncomplicated box and its installation is direct and straightforward. We ensure that our product caters to the needs of both, the IT and the operational teams, equally.
  • We offer Packaged Cybersecurity by ensuring a complete package that caters to your every cybersecurity need. Our software is well-equipped to handle asset discovery, carry out mapping and initiate network segmentation seamlessly. We ensure all these essential steps are intertwined in a cohesive manner to facilitate the optimal functioning of your security measures.
  • Our product is capable of Advanced Detection . Built-in detection features run in the background to efficiently detect threats and alert the users about any potential threat. Further, our product also integrates built-in compliance frameworks. These guidelines help our customers in successfully implementing the most effective security controls for their business operations.

Adding these capacities allow us to provide a unique First-mile Cybersecurity appliance.Below is a 2 minutes video of Theo (co-founder at Trout Software) presenting this solution.

About Trout Software

Trout Software has developed tools to enable business and IT teams to strengthen the cybersecurity of their environments - both IT and OT - and to accelerate their certification processes (documenting security policies and collecting evidence). The company is based in France with offices in Dublin and New York, and works with customers such as Thales, Orange and Signal Iduna.

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