IEC 62443 and Network Segmentation

The industrial cybersecurity landscape is undergoing a significant transformation. In 2025, the convergence of IT and OT networks will accelerate, coupled with the increasing sophistication of cyber threats, which is making robust network segmentation more critical than ever for Industrial Control Systems (ICS) environments. The IEC 62443 standards are evolving to meet these challenges, with significant updates reshaping how organizations approach network security, particularly in manufacturing, industrial, and healthcare sectors.

Current State of IEC 62443 Segmentation

Traditional approaches to network segmentation under IEC 62443 have relied heavily on the zones and conduits model. While effective for basic security needs, these methods often struggle with the complexity of modern industrial environments. The traditional framework, which primarily focuses on Layer 3 segmentation, has shown limitations in addressing the sophisticated threat landscape of 2024 and beyond.

Legacy systems present a particular challenge, as noted in the 2024 revision of IEC 62443-2-1. The standard acknowledges that IACS systems can exceed 20-year lifespans, requiring organizations to manage hardware and software that may no longer receive vendor support. This reality has pushed the evolution of segmentation strategies beyond conventional boundaries.

Key 2025 Changes in IEC 62443

The 2025 updates to IEC 62443 introduce several significant changes to network segmentation requirements. Key among these is the enhanced focus on microsegmentation, particularly below Layer 3. The standards now emphasize more granular control through zones and conduits, especially for environments with mixed TCP/IP and non-IP-based communications.

Regulatory bodies are increasing pressure for organizations to adopt microsegmentation as part of their zero-trust architecture implementation. This shift reflects the growing recognition that traditional perimeter-based security is insufficient for today's threat landscape.

Evolution of Segmentation Techniques

Modern segmentation techniques now incorporate advanced zone management capabilities and software-defined security zones. Identity-based microsegmentation has emerged as a crucial component, enabling organizations to implement dynamic security policies based on device and user identity rather than just network location.

This evolution enables real-time monitoring of traffic between zones, providing greater visibility into potential threats while they're in transit. The approach allows organizations to maintain security without sacrificing operational efficiency.

Implementation Strategies

Successful implementation of the new IEC 62443 requirements demands a structured approach to operational zone organization. Organizations must focus on:

1. Asset Discovery and Classification

• Continuous monitoring of device inventory
• Automated classification of assets natively or by integrating with a Cyber Asset Attack Surface Management (CAASM) or Cyber-Physical Systems (CPS) Protection Platforms like Armis, Claroty, Medigate or Nozomi
• Integration with existing CMDB and ITSM asset management systems

2. Policy Enforcement

• Dynamic policy updates based on identity, vulnerabilities, and risks
• Automated enforcement mechanisms
• Real-time adaptation to network changes

Impact on Industrial Operations

The new standards recognize the complexity of industrial environments, where diverse communication protocols must coexist. Protection of legacy systems remains a priority, with the standards providing frameworks for implementing compensating controls when native security capabilities are absent.

Integration with existing security controls requires careful consideration of operational impacts. The standards emphasize the importance of maintaining operational efficiency while enhancing security measures, particularly in environments where downtime is not an option.

Compliance and Standards Alignment

The 2025 requirements align closely with other major frameworks, including NIST and ISO 27001. This alignment helps organizations maintain compliance across multiple standards while implementing a cohesive security strategy. The standards now provide clearer guidance on audit requirements and reporting capabilities, making compliance verification more straightforward.

The Growing OT Attack Surface

Recent trends show a dramatic increase in attacks targeting OT environments. The convergence of IT and OT networks has expanded the attack surface, making industrial systems more vulnerable to sophisticated cyber threats. According to recent data, connectivity to external systems continues to be the predominant root cause of incidents, indicating that many enterprises still struggle with implementing effective network segmentation.

Zero-Trust Microsegmentation: A Strategic Imperative

As organizations work to meet IEC 62443 requirements, zero-trust microsegmentation emerges as a key strategy. This approach enables enterprises to rapidly improve their security posture while reducing risks and accelerating their zero-trust maturity. The technology allows for granular control over all users, workloads, and devices across the network.

Modern microsegmentation solutions, designed for rapid implementation without downtime, can discover and classify every network asset automatically. This capability, combined with identity-based security policies, provides the control and visibility required by the updated IEC 62443 standards.

Future Outlook

Looking ahead, emerging segmentation technologies will continue to evolve, incorporating AI and automation to enhance threat detection and response capabilities. Industry adoption trends suggest accelerating the implementation of microsegmentation solutions, particularly in critical infrastructure sectors.

Read the Forrester Wave™ Microsegmentation Solutions, Q3, 2024, and learn why Forrester calls this the Golden Age of Microsegmentation.

The 2025 updates to IEC 62443 represent a significant evolution in industrial cybersecurity standards. Organizations must prepare by adopting more sophisticated segmentation strategies, particularly zero-trust microsegmentation. Success requires a balanced approach that considers people, processes, and technology while maintaining operational efficiency.

Strategic recommendations for organizations preparing for these changes include:

• Implementing identity-based microsegmentation solutions that can scale across the enterprise
• Developing comprehensive asset discovery and classification processes
• Establishing automated policy enforcement mechanisms
• Creating clear procedures for managing segmentation across both IT and OT environments

By taking these steps, organizations can not only meet compliance requirements but also significantly enhance their security posture against evolving threats. 

When you are ready to enhance your cybersecurity with state-of-the-art microsegmentation, schedule a call or demo with Elisity and learn how our solutions enable manufacturers, industrial organizations, and their critical infrastructure leaders to ensure compliance and maintain operational excellence in the face of evolving cyber threats.