The security of your network is critical, and segmenting it is one of the most effective strategies to enhance your posture. This technique reduces your attack surface and improves overall network performance. 

Let’s explore the top network segmentation best practices for maintaining a secure and efficient network.

1. Visualize Your Network

Before implementing segmentation, it’s crucial to have a clear understanding of your current network architecture. Visualizing your network allows you to identify existing traffic flows, communication patterns, and potential vulnerabilities. Use network mapping tools to create a detailed diagram of your network, highlighting key assets, connections, and data flows.

2. Identify and Label Asset Values

Not all assets are equal, so it’s important to identify and label asset values based on their importance, sensitivity, and criticality to the organization. High-value assets, such as databases containing sensitive customer information or financial systems, should be placed in highly secure segments with restricted access.

By categorizing assets, you can apply appropriate security controls and prioritize protection efforts where they are most needed.

3. Combine Similar Network Resources

To simplify change management and improve efficiency, combine similar network resources into the same segment. For example, group all devices or applications that perform similar functions or belong to the same department into a single segment. This approach reduces the complexity of managing multiple segments and ensures that resources with similar security requirements are protected consistently.

4. Follow the Principle of Least Privilege

The principle of least privilege is a fundamental security practice that should be applied to network segmentation. This principle states that users and devices should only have the minimum level of access necessary to perform their tasks. By enforcing this principle, you can limit the potential for unauthorized access and reduce the risk of insider threats.

Ensure that each segment has strict access controls in place, and regularly review and update permissions to align with current security policies.

5. Limit Third-Party Access

Third-party vendors and partners often require access to your network, but this access should be tightly controlled. Network administrators should limit third-party access by creating dedicated segments for external entities, ensuring that their access is restricted to only the resources they need. Additionally, monitor third-party activity closely to detect any suspicious behavior or potential data breaches.

6. Use a Combination of Segmentation Techniques

There is no one-size-fits-all approach to network segmentation. Instead, organizations should use a combination of segmentation techniques to achieve the best results. For example, combining VLANs with firewall rules or micro-segmentation can provide both broad and granular controls, enhancing overall security and flexibility.

7. Avoid Over or Under-Segmentation

Over-segmentation can lead to unnecessary complexity and administrative overhead, making it difficult to manage and monitor the network effectively. On the other hand, under-segmentation can leave critical assets exposed and increase the risk of breaches. Striking the right balance is key—create enough segments to isolate critical resources and minimize risk, but not so many that it becomes unmanageable.

8. Create Legitimate Data Paths

When segmenting your network, ensure that there are legitimate data paths between segments that need to communicate. Unauthorized or unnecessary communication channels can create vulnerabilities and increase the risk of lateral movement by attackers. Use internal firewalls, ACLs, and other security measures to control and monitor data flows between segments, ensuring that only authorized traffic is allowed.

9. Implement Endpoint Security and Protection

Network segmentation is not a standalone solution; it should be complemented with endpoint security and protection measures. Ensure that all devices connected to the network are secured with antivirus software, encryption, and regular updates. Endpoint security is critical in preventing malware or unauthorized access from compromising network segments.

Additionally, implement policies for device management, such as restricting the use of personal devices or ensuring that all endpoints meet security standards before connecting to the network.

10. Audit and Monitor Your Network

Regular auditing and continuous monitoring of your network segments are essential for maintaining security and regulatory compliance. Use tools to track network traffic, detect anomalies, and respond to potential threats in real time. Conduct periodic audits to assess the effectiveness of your segmentation strategy and make necessary adjustments to improve security and performance.

Implementing a robust monitoring system also helps in maintaining security hygiene by identifying and addressing vulnerabilities before they can be exploited.

Implement the Best Practices for Network Segmentation with FireMon

To enhance your network segmentation efforts, consider integrating a solution like FireMon into your security strategy. FireMon provides advanced tools for asset management, continuous compliance, and attack surface management (ASM), helping organizations maintain a secure and resilient network.

When managing network policies, it’s important to have real time visibility of changes and their effect on your network. FireMon’s Network Security Policy Management (NSPM) platform allows you to take a proactive approach to network security, enabling you to enforce compliance, manage risk, and optimize your segmentation strategy. 

Book a demo today and discover how FireMon can help ensure your strategy aligns with network segmentation best practices.

Frequently Asked Questions

What Is Network Segmentation?

Network segmentation is the practice of dividing a computer network into smaller, distinct sub-networks, or segments, to improve security and performance. These segments can be based on various criteria, such as user roles, device types, or data sensitivity. By isolating parts of the network, organizations can control traffic flow, restrict unauthorized access, and contain potential breaches to a limited area.

Segmentation of networks can be implemented using different technologies, including: 

• Virtual Local Area Networks (VLANs) 
• Firewalls 
• Software-defined networking (SDN) 

Proper segmentation allows for granular, complete control over who and what can access specific network resources, significantly enhancing the organization’s security posture.

“Network segmentation really involves creating a collection of whatever devices and assets happen to be in that segment, what I call a zone of control,” said Tim Woods, VP of Technology Alliances at FireMon. “That could be computers, it could be servers, and in today’s world, it could be IoT.”

How Does Network Segmentation Work?

Network segmentation works by dividing a network into smaller segments, each isolated from the others. This segmentation limits access to resources within each segment, controlling traffic flow and containing potential breaches. Segmentation can be achieved through various technologies, such as VLANs, firewalls, and SDNs, which enforce the rules and policies that govern how data flows between segments.

What Are the Types of Network Segmentation

There are several types of network segmentation that organizations can implement, each serving different purposes:

Why Is It Necessary to Segment a Network?

Segmenting is necessary to improve network security, compliance, and operational efficiency. It reduces the attack surface, limits lateral movement by attackers, and helps contain breaches within specific segments. Additionally, segmentation simplifies the enforcement of security policies and compliance with regulatory requirements.

How Does Network Segmentation Differ from Internal Segmentation?

Network segmentation involves dividing the entire network into distinct segments, while internal segmentation refers to creating additional security boundaries within a segment, often to protect sensitive data or critical applications. Internal network segmentation is typically more granular and is used to apply stricter security controls within a specific part of the network.

*** This is a Security Bloggers Network syndicated blog from FireMon.com authored by FireMon. Read the original post at: https://firemon.com/blog/network-segmentation-best-practices/