Network segmentation is vital because it separates systems and devices to limit unauthorized access and cybersecurity threats. Modern software enhances network segmentation with advanced artificial intelligence (AI) capabilities and real-time threat detection.

Network segmentation divides a computer network into subnetworks, enabling you to control traffic flow between smaller, distinct segments rather than operating on a flat network. A segmented network enhances security by limiting or blocking access to certain areas within it. It limits lateral movement, making it harder for cyber criminals to move from one system or device to another if they gain initial access. Network segmentation is vital because it offers the following advantages:

Enhanced security

Strong network segmentation prevents cyber attackers from moving sideways across your network, accessing sensitive data, gaining privileges, and reaching their main target. It helps you create a separate, more specific security policy for each part of your network, which is crucial for combating modern cyber criminals and innovative attacks.

Improved network performance

Segmentation can improve network performance by isolating different types of traffic to specific network segments. This reduces congestion and ensures critical systems receive the necessary bandwidth to carry out their functions. When you implement quality segmentation, you can expect improved network efficiency and faster response times.

Compliance and risk mitigation

Protecting systems and sensitive information from unauthorized access helps your company comply with data protection regulations. You can use network segmentation to clearly define boundaries and manage different types of sensitive data that fall under compliance regulations such as the Payment Card Industry Data Security Standard (PCI DSS).

Consider how the following types of network segmentation differ:

Physical

Physical segmentation relies on hardware such as routers, switches, and firewalls to segment a network. It's a secure solution, but it's challenging to manage and less scalable than virtual methods.

Logical

Logical segmentation methods such as software-defined networking (SDN) and virtual local area networks (VLANs) use software-based configurations to divide networks into smaller, isolated network segments:

• VLANs: VLANs route traffic to the appropriate segments via data packets containing. Data packets contain VLAN tags that route traffic to the appropriate subnet or segment.
• SDN: SDN often offers more flexibility and isolation than VLANs because it differentiates the data plane from the network control plane. Modern SDN solutions also enable micro-segmentation, which gives you more precise control over the information certain users can access and which actions they can take.

Logical segmentation facilitates more flexible traffic control and network management than physical implementation. You can implement your segmentation in code and update boundaries as your network grows and evolves.

OT network segmentation applies network segmentation to operational technology networks that control industrial processes. While network segmentation focuses on cybersecurity concerns, OT segmentation requires a unique approach because it must also prioritize safety and operational reliability. It must support real-time industrial equipment control, help maintain operational stability, and meet strict compliance standards.

OT segmentation separates a company's IT network from its industrial control system. You can also use OT segmentation to further separate your control system into different zones, minimizing the impact in the event of a cyber-attack.

Implement the following best practices to optimize your network segmentation and enhance security:

Define each segment based on roles and criticality

Inventory your organization's assets and categorize them based on value and potential risk. Focusing on your high-risk or high-value assets first ensures you protect them properly and that your segmentation policy provides the greatest return on investment (ROI). Clearly defining each segment based on its roles and criticality is the first step to organizing your network and maximizing its protection.

Map your organization's business flows

To identify critical points and define segment boundaries, you must understand how information and data flow throughout your network. Mapping business flows helps ensure your network segmentation supports your operations and protects your most sensitive information. You can map business flows in the following steps:

• Document key processes: Identify your organization's key processes, documenting how data travels between different departments and systems.
• Analyze data interactions: Analyze how applications, users, and databases interact with data as it flows through your network.
• Prioritize critical segments: Use your business flow mapping to determine which network segments are connected to your most critical data and functions so you can prioritize them in your policies and cybersecurity measures.

Define clear policies

Once you understand your network's infrastructure, you can define segmentation policies based on your needs and each asset's sensitivity. For example, you may group a database and an application in one segment but place a critical system within the same department in a separate segment. Document each policy and the logic behind it to ensure auditability, consistency, and security.

Use strategic firewalls

Internal firewalls inspect traffic before allowing it past segment boundaries. Appropriately configured firewall rules are essential and should accomplish the following:

• Reflect and support corporate security policies
• Enforce appropriate access controls
• Minimize their effect on necessary business operations

Use the least privilege principle to strengthen access controls

It's vital to limit segment access to the users, applications, and devices that require it. For example, you might grant your accounting department access to online financial data but deny your marketing team access to this sensitive information. You can implement least privilege in your network segments with the following tips:

• Limit each user's access to only the systems necessary to do their jobs
• Limit each device or application's access to only the systems necessary to carry out its function
• Restrict or limit communication between segments with strong access controls
• Regularly audit and update access permissions

Role-based access control (RBAC) is an effective, scalable solution because it grants permission to a specific role, which you can then assign to an entity or user. Supporting access controls with security best practices such as multi-factor authentication (MFA) strengthens boundaries and minimizes cyber-attack risks.

Plan your network segmentation for scalability

Choose technologies and tools that can grow with your organization. Logical network segmentation methods such as SDN and VLANs are the best options because of how well they can scale with business changes and growing systems.

Implement AI technology

AI plays a vital role in network segmentation due to its advanced threat detection capabilities, and it's another way to enhance scalability. It analyzes traffic patterns with real-time data, identifying potential security threats and automatically adjusting segmentation rules.

Darktrace / OT is a comprehensive security solution built specifically for critical infrastructure. It implements real time prevention, detection, and response for operational technologies, natively covering industrial and enterprise environments with visibility of OT, IoT, and IT assets in unison.

Using Self-Learning AI technology, Darktrace / OT is the industry's only OT security solution to scale bespoke risk management, threat detection, and response, catching threats that traverse network- and cloud-connected IT systems to specialized OT assets across all levels of the Purdue Model.

Instead of depending on knowledge gained from past attacks, AI technology learns what "normal" usage is for its environment and identifies previously unknown threats by detecting slight pattern variations. This gives engineering and security teams the confidence to evaluate workflows, maintain security posture, and effectively mitigate risks from a unified platform in less time.

Read more about Darktrace / OT in our solution brief here.

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