What is the Role of Network Segmentation in Cybersecurity and How Does it Work?

Network segmentation, also known as network partitioning or zoning, is the practice of dividing a computer network into smaller, isolated subnetworks, known as segments or zones. This strategy can also be referred to as network isolation or subdividing, depending on the specific context and goals. By enhancing security, reducing attack surfaces, and improving network performance, network segmentation plays a crucial role in maintaining organizational integrity and operational efficiency. Its application is varied, serving different needs across industries and organizational structures.

What is Network Segmentation?

Network segmentation is a fundamental network security strategy that involves dividing a large, flat computer network into smaller, independent subnetworks or segments. Each segment is isolated from the others, operating as its own mini-network with defined access controls and security policies. This process enhances network segmentation security and helps in maintaining the health of a segmented network.

The primary objective of network segmentation is to improve overall cybersecurity by limiting the lateral movement of threats and potential attackers within the network. In a traditional flat network, where all devices and systems are part of a single domain, a breach in one part could grant attackers access to sensitive resources throughout the entire infrastructure. Network segmentation mitigates this risk by creating barriers between segments, ensuring that in the event of an attack, the attacker’s access remains limited to a specific zone.

How Does Network Segmentation Work?

Various techniques and strategies are used to create network segments in order to safeguard organizational assets from the risks of lateral movement if a hacker gets in.

Network Segmentation Techniques

Different techniques can be used in network segmentation, each catering to specific needs and offering unique advantages:

• VLAN Segmentation: VLAN (Virtual Local Area Network) segmentation is a network segmentation tool that divides networks into smaller network segments, yet allows different devices to communicate as if they are part of the same physical network, regardless of their actual physical location. It effectively manages traffic and reduces congestion by grouping devices with similar requirements.
• Subnetting: This network segmentation technique divides an IP network into smaller, more manageable pieces. By isolating different parts of the network, subnetting improves performance and security, offering a systematic way to organize and protect network resources.
• ACLs (Access Control Lists): ACLs are used to control user access within a network, thereby enhancing network segmentation security. They define rules that grant or deny permissions to specific IP addresses, contributing to a more secure and controlled environment.

Microsegmentation is another network segmentation technique that takes segmentation to a more granular level. Unlike traditional methods, which typically segment the network at the switch or router level, microsegmentation isolates individual workloads, providing more precise control over data flow and interactions. By applying security policies at a micro-level, organizations can have a more targeted defense against potential threats, reducing risks and adding an extra layer of protection.

Implementation Strategies for Network Segmentation

Network segmentation, vital for enhancing security and improving performance, can be implemented through two main strategies, each catering to unique needs and environments:

Physical Network Segmentation

Physical network segmentation involves creating distinct network segments using separate physical devices like switches or routers. This approach provides a robust separation, with each segment physically isolated from the others.

Advantages

• • Security: Ensures a high level of protection by physically separating segments.
  • Performance: Enhances network performance and reduces congestion by isolating network traffic.

Disadvantage

• • Cost and Complexity: This method may involve higher costs and increased complexity due to additional hardware requirements.
    Physical Network Segmentation Example: Data centers might apply physical network segmentation to separate different customers’ environments or isolate mission-critical systems.

Logical Network Segmentation

Logical network segmentation is achieved through software, utilizing technologies like VLANs (Virtual Local Area Networks) or firewall rules. It allows for flexibility and scalability, adapting to the organization’s evolving needs.

Advantages

• • Flexibility: Permits the creation of adaptable network segments without the need for additional physical hardware.
  • Scalability: Can be easily expanded as the organization grows to include new systems or users.
  • Cost-Effectiveness: Usually requires less investment in hardware, making it a more cost-efficient solution.

Disadvantage

• • Security Considerations: While offering flexibility, logical segmentation must be carefully configured and monitored to ensure robust security.

Logical Network Segmentation Example: A university might implement logical network segmentation to separate student, faculty, and administrative networks, allowing for tailored access controls and security policies for each group.

Choosing the Right Strategy

Selecting the right network segmentation strategy depends on factors such as organization size, security requirements, budget constraints, and existing network infrastructure. A combination of both physical and logical segmentation might also be considered to allow the organization to realize the benefits of both approaches. Consultation with network security experts along with a thorough assessment of the organization’s needs and risk factors should guide the decision-making process. This ensures that the chosen strategy aligns with the organization’s overall security posture and operational goals, making the most out of network segmentation’s potential benefits.

Benefits of Network Segmentation

Network segmentation plays a pivotal role in enhancing an organization’s security and efficiency. By isolating different parts of a network, segmentation offers more controlled access and optimized performance. Whether it’s protecting sensitive information, stopping the spread of potential cyberattacks, or meeting specific regulatory compliance requirements, the benefits of network segmentation are broad and diverse. Let’s explore these advantages in more detail across different scenarios and applications:

Improve Operational Performance

Segmentation minimizes network congestion, enhancing overall operational performance. For example, in a hospital, medical devices can be segmented from the visitor network, ensuring that essential medical functions are unaffected by heavy web browsing. In a corporate environment, segmentation can separate different departments, ensuring that critical business applications run smoothly without interference from other departments’ network traffic.

Limit Cyberattack Damage

Segmentation strengthens cybersecurity by restricting malware penetration and spread in the event of an attack. For instance, if malware infects one section of a business network, segmentation can prevent it from spreading to other areas. In an educational institution, segmentation could isolate student devices from administrative systems, thus preventing a potential breach initiated via a student device from impacting sensitive administrative data.

Facilitate Network Monitoring and Troubleshooting

Network segmentation in a large manufacturing company can separate production line systems from office workstations, enabling more efficient monitoring and troubleshooting. This allows IT teams to quickly identify and address issues in specific segments, minimizing downtime and proactively managing potential problems.

Protect Vulnerable Devices

Segmentation can shield devices that lack advanced security defenses from harmful traffic. For example, a hospital’s connected infusion pumps may not have robust security mechanisms, and network segmentation can prevent dangerous Internet traffic from reaching them. Similarly, in an industrial setting, segmentation might be used to protect legacy machinery and control systems that were not designed to withstand modern cybersecurity threats.

Enhance Privacy and Data Protection

Network segmentation can safeguard privacy and protect sensitive data by isolating specific segments that handle confidential information. For instance, a law firm may implement network segmentation to separate client case files and legal documents from general office applications and email. This segmentation ensures that only authorized personnel have access to sensitive legal data, thereby maintaining client confidentiality and complying with professional standards and regulations.

Reduce the Scope of Compliance

Segmentation narrows regulatory compliance scope and costs by isolating specific systems. For instance, in PCI Compliance, it separates payment processing from non-payment systems, applying stringent requirements only where necessary. Similarly, in healthcare, segmenting patient data from administrative systems can narrow the scope of HIPAA compliance, simplifying the process and reducing expenses.

Network Segmentation Best Practices and Tools

Effective network segmentation involves following best practices and employing the right tools. Guidelines include proper planning, identifying the right VLAN segmentation strategy, utilizing network segmentation diagrams for clear visualization, and continuous monitoring.

Why Network Segmentation is Important to Ericom

Network segmentation plays a vital role in Ericom’s approach to providing robust cybersecurity solutions for its customers. Through network segmentation, Ericom solutions deliver on the Zero Trust principle of least privilege access through network architecture and microsegmentation.

Zero trust network access (ZTNA) architecture minimizes attack surfaces by implementing least-privilege access controls, microsegmentation, and identity controls, like multi-factor authentication (MFA). By replacing vulnerable VPNs, which enable users (or hackers) to move laterally across networks, ZTNA ensures that trust is never implicitly given or too broadly granted. Instead, users may access only the specific resources for which they are verified as authorized users.