What Is Network Segmentation? How It Works & Why It Matters

Network segmentation is dividing a computer network into smaller subnetworks or segments. Each segment can act as its own small network, which can help increase network performance and enhance security.

Network segmentation allows for better control over traffic flows and isolates network issues, reducing the impact on the whole network. It can also help prevent unauthorized access to sensitive information by keeping that information on a separate segment isolated from general network traffic.

Nile implements network segmentation and isolation through its zero trust security model, which is extended to the enterprise campus and branch to reduce the attack surface across the enterprise local area network (LAN).

This model mandates secure network access across Wi-Fi access points and wired access switches, ensuring that only authorized users and devices can access the network.

Nile Access Service orchestrates user/device level isolation after mandating secure network access, completely eliminating the risk of malware proliferation via the use of layer 2 (L2) networking with Virtual LANs (VLAN) and by eliminating the need for static Access Control Lists (ACL) across wired/Wi-Fi connectivity at the network edge.

A Nile network uses dynamic rules for network access controls next to complete isolation, enabling continuous authorization across all connected mobile and IoT devices. It centralizes all traffic, and shares user/device attributes with firewalls to protect against threats.

Unencrypted traffic flows, traffic from unknown users and devices, and unknown applications can mean increased risk and high cyber insurance costs for many organizations. In these scenarios, certain Nile network segments such as guest user traffic can be tunneled to Nile’s point-of-presence (PoP) to keep them completely isolated from IT resources across the campus and branch locations.

How does segmentation work?

Network segmentation works by dividing a network into smaller subnetworks or segments. Typically, this division is done based on specific criteria such as function, team, or project. For example, a company may have a separate segment for its sales department, technical team, and administrative staff.

Each of these separate segments is effectively its own mini-network with its own set of rules, policies, and access controls. Security controls are applied to each segment to manage and monitor network traffic within and between segments. For instance, the sales department may not need access to the same applications and sensitive customer data as the technical team, so they are placed in different segments with different access controls.

This segmentation helps to limit the spread of potential cyber threats. If a threat infiltrates one segment, it’s contained within that segment and cannot spread to other network parts.

Network segmentation can also significantly boost network performance. By breaking a larger network into smaller segments, firms can reduce network congestion and improve the speed of network connections within each segment.

Segmentation can be achieved physically through separate hardware like switches and routers, but it’s often achieved logically using software controls in devices like firewalls or protocols such as Virtual Local Area Networks (VLANs).

Ultimately, network segmentation works by reducing a large, complex network into smaller, more manageable segments, improving both security and performance.

This traditional use of VLANs has been replaced by fully isolated virtual segments within a Nile network: eliminating the possibility of connected devices potentially impacting each other’s security posture (e.g. malware proliferation).

Types of network segmentation

There are two main types of network segmentation:

1. Physical network segmentation: This method involves physically separating networks using separate hardware such as routers, switches, and firewalls. Each network segment physically stands alone from the others, which can increase security and cost and maintenance efforts.
2. Logical network segmentation: This method uses software tools to divide a single physical network into multiple isolated networks. Logical segmentation often involves techniques such as VLANs, subnetting, and virtual private networks (VPNs). This method is more flexible and cost-effective but may not provide as much security as physical segmentation.

Sub-categories within these include:

• VLAN Segmentation: Creating separate, isolated subnetworks within a larger network using VLANs, managing traffic, and bolstering security.
• Subnetting: Breaking up a network into smaller sections called subnets to improve performance and security.
• VPNs: A form of logical segmentation that creates secure, private networks across public networks.
• Firewall Segmentation: Using firewall rules to create boundaries and control traffic between different network segments.
  Software-Defined Networking (SDN) Segmentation: Utilizes software and cloud-based services to divide and secure network traffic.

Aside from these methods, the concept of ‘micro-segmentation’ has also been introduced, which involves segmenting even smaller portions of a network to achieve more granular control over traffic and greater security.

In a Nile network, each authenticated and authorized device that has been allowed to sit on the campus and branch network “lives within its own bubble” by default. This requires no extra hardware / software components that need to be configured in order to create such a perimeter to protect users, data and assets. By extending zero trust networking principles to the edge networks across campus and branch locations, Nile completely eliminates traditional requirements to utilize VLANs as a network security perimeter.

Network segmentation examples

A typical example of network segmentation can be seen in corporate organizations. A company’s network infrastructure might be divided into several segments based on departments: the finance department, human resources, operations, etc. Each department’s segment may have specific access rules and security controls relevant to their role and the kind of data they handle.

Consider a college campus scenario where the administrative office needs access to certain confidential databases and systems that other campus departments do not require. Through network segmentation, the administrative office functions within its dedicated network segment, isolated from individuals in other campus departments.

This approach ensures that even if there is a security breach in another department’s network, the administrative office’s network segment and its sensitive data remain secure. Attackers cannot breach this segment, thus safeguarding critical academic and administrative information. This strategy aids colleges in bolstering their security measures, preserving the confidentiality of sensitive data, and adhering to privacy regulations.

How to implement network segmentation?

Evaluate existing infrastructure

Begin the process by gaining a comprehensive understanding of the current network setup. This involves identifying all connected devices, their respective roles, and the data types they handle.

Classify data and assets

Prioritize data classification based on its sensitivity and criticality. Give special attention to high-risk and compliance-related data.

Plan the segments

Strategically plan the creation of different network segments, aligning them with the data classification. For instance, consider establishing separate segments for servers handling sensitive data, user endpoints, and IoT devices.

Design segment controls

Create specific controls and policies tailored to each network segment. This includes determining user access permissions, defining access levels, and specifying authentication requirements.

Implement segmentation

Physically or virtually implement the planned network segments using tools such as firewalls, VLANS, or SDNs.

In a Nile network, all you need to do is to create your segments and by design, each authorized device will be isolated from any other device.

Test your segmentation

After the implementation, thoroughly test the network segmentation to ensure it operates as intended. Challenge the segments to identify potential vulnerabilities and weaknesses.

Monitor and adjust

Regularly monitor each network segment for security threats and issues post-segmentation. Adjust and refine segment restrictions as necessary to effectively manage security threats.

Provide training

Provide training to your staff, particularly those with administrative access, emphasizing the importance of network segmentation and how to manage it effectively.

Benefits of network segmentation

Improved security

One of the primary reasons for network segmentation is to enhance security. By dividing the network into separate segments, security breaches can be contained and prevented from spreading across the entire network.

Enhanced performance

By splitting a network into segments, traffic is reduced, which can lead to better network performance and speed. This can be especially beneficial for organizations with many users or devices.

Easier troubleshooting

It is easier to identify and isolate issues on a segmented network. When a problem arises in a particular segment, it can be addressed without impacting the entire network.

Regulatory compliance

Certain regulations and standards require network segmentation. For example, the Payment Card Industry Data Security Standard (PCI DSS) often requires companies to segment the part of their network that handles cardholder data from the rest of their network.

Reduced impact of cyber attacks

If a cyber attack does occur, its impact can be significantly reduced. Controlling threats to a specific segment makes it harder for them to infiltrate the entire network.

Privacy protection

Network segmentation can also protect privacy by limiting the exposure of certain sensitive and confidential data only to authorized persons or devices.

Resource management

Segmentation allows for easier resource management, as it’s possible to assign specific resources to different segments according to the needs of the organization.

Limiting unwanted traffic

Network segmentation can limit unnecessary traffic to certain parts of the network, improving overall performance and potentially reducing bandwidth costs.

Simplified IT management

With segmentation, IT teams can more easily manage and control network operations across different departments or functional areas.

Better control over access

Network segmentation allows for greater control over who can access what, increasing overall network security and privacy.

Network segmentation disadvantages

While network segmentation offers numerous benefits, it also has several disadvantages.

Complexity

Implementing network segmentation involves meticulous planning, constant attention, and management. Regular auditing and monitoring of measures are necessary to ensure efficiency.

Cost

Implementing network segmentation can be expensive, especially in large systems. The cost also extends to the maintenance and potential need for increased staffing.

Setup time

Properly implementing a fully segmented network can take an extended period, especially in a large organization with a complex network infrastructure.

Overhead maintenance

Every segment created needs to be managed and monitored, which increases the administrative overhead.

Misconfigurations

Incorrect implementations can lead to increased vulnerability instead of enhanced security. Misconfigured rules or policies can lead to loopholes attackers can exploit.

Effects on network performance

If not properly designed and implemented, network segmentation can potentially lead to bottlenecks and negatively impact the overall network performance.

Scalability issues

As an organization grows, its network needs to evolve. Scaling up a segmented network can take time and effort.

Increased complexity for users

Users may need to use different credentials or go through additional steps to access different network segments, which can decrease usability and productivity.

That’s primarily the reason why all of the steps below are completely automated with the Nile Access Service thanks to its vertically integrated software and security architecture. All of the steps below can be completed by network administrators with a single or few steps, saving more than 90% of the complexity that have been experienced with traditional product centric technology solutions for wired and wireless access networks.

Network segmentation best practices

1. Understand your network

   Before you start segmenting your network, you have to understand it thoroughly. You need to know how traffic flows, where sensitive data resides, who needs access to it, and how users and systems interact.

2. Identify and categorize assets

   Classify your network assets like servers, workstations, and IoT devices based on their functions, sensitivity, and criticality. This will help you to prioritize your network segmentation efforts.

3. Start with high-risk areas

   Begin by segregating the most sensitive parts of your network. These could be servers hosting sensitive data, payment systems, or business-critical applications.

4. Follow the principle of least privilege

   Every segment of your network should have just the right amount of access it needs to perform its function and nothing more. This limits the potential damage in case of a breach.

5. Validate all changes

   Network segmentation, if done incorrectly, can introduce disruptions or even take parts of your network offline. Always test and validate changes in a controlled environment before implementing them in your live network.

6. Continually monitor and audit

   Network segmentation is not a one-time task. Networks evolve over time, so monitor your network for changes and ensure your segmentation strategies keep pace.

7. Implement full isolation

   This involves segmenting a network right down to the individual workloads or process level. It provides a more granular form of control, allowing for effective containment of threats.

8. Automate

   Automate the segmentation process wherever possible to reduce the manual labor involved, reduce errors, and ensure timely implementation.

9. Policies and procedures

   Create and enforce strict policies about who can access what resources. Document these policies, regularly update them, and ensure they are followed.

10. Education and training

    All stakeholders should understand what network segmentation is and why it is important. Regular training can ensure that they comply with the policies and contribute towards a safer network environment.

Automated network segmentation and isolation

Network segmentation, isolation of authorized devices and protection from unknown devices (e.g. guest users) doesn’t have to be complicated.

Nile Access Service relieves you of the burden of designing, segmenting, and securing the network yourself. It offers a seamless network experience that aligns with your strategic requirements, by starting with zero trust network access principles built-in to the infrastructure.

Nile Access Service eliminates inefficiency that have crippled legacy network architectures, reduces high up-front costs, and handles the challenge of managing and maintaining your enterprise network. Get in touch and let’s discuss how we can radically streamline wired and wireless access network security across your campus and branch locations.