Network Segmentation Explained in Layman Term

Network segmentation controls the flow of traffic and improves network performance.

It is important for organizations to prioritize network security in this digital world where data breaches and cyber threats are on the rise.

One effective strategy that can significantly enhance network security is network segmentation.

In this article, we will discuss the concept of network segmentation and its role in network security, along with its real-world applications.

Let’s get started!

What is Network Segmentation?

Imagine you have a big house with multiple rooms. Each room serves a different purpose, like a bedroom, kitchen, or living room. Now, think of your computer network as a similar house – but instead of rooms, it has different parts that connect your computers and devices.

Network segmentation is like dividing your house into smaller sections or rooms. Each section has its own purpose and is separate from the others. This separation helps to keep things organized and secure.

In the context of a computer network, segmentation means splitting the network into smaller parts. Each part, or segment, contains a specific group of computers or devices that have something in common, like belonging to the same department or needing similar security measures.

The primary goal of network segmentation is to control the flow of network traffic and limit access to sensitive information, which reduces the attack surface for potential threats.

Role of Network Segmentation in Network Security

Organizations can separate their network into logical units based on factors such as departments, functions, security requirements, or user roles by implementing network segmentation.

This segregation prevents unauthorized access and restricts the spread of potential threats within the network.

In other words, even if one segment of the network is compromised – the impact is contained within that specific segment which prevents the attacker from easily moving laterally to other parts of the network.

It’s like having a door between rooms that you can close to prevent something bad from affecting the rest of the house.

Benefits of Network Segmentation

Network segmentation offers several benefits for organizations. Here are some of the key advantages:

Enhanced Security

As discussed above, Each segment acts as a barrier that limits the impact of potential security breaches. Even if one segment is compromised – the attacker’s access is contained within that segment.

It helps to protect sensitive data from unauthorized access.

Reduced Attack Surface

The potential targets for attackers are limited by dividing the network into smaller segments.

It becomes more challenging for them to infiltrate the entire network as they need to overcome multiple barriers and security measures to move from one segment to another.

Improved Network Performance

It can enhance network performance by reducing congestion and optimizing the flow of traffic.

Important applications and services can be prioritized within specific segments, which ensures that they receive the necessary bandwidth & resources without being affected by other network activities.

Compliance with Regulatory Requirements

Many industries have specific regulatory requirements regarding data privacy and security.

Network segmentation helps organizations meet these compliance standards more effectively.

Organizations can make sure that they stay true to industry-specific regulations such as PCI DSS, HIPAA, or the General Data Protection Regulation (GDPR) by isolating sensitive data and applying access controls.

Simplified Network Management

Managing a large, monolithic network can be complex and time-consuming. Network segmentation simplifies network management by dividing the network into smaller and more manageable segments.

IT teams can focus on each segment individually, which makes it easier to monitor, troubleshoot, and implement changes or updates.

Isolation of Network Resources

Organizations can isolate specific network resources based on their function or security requirements.

For example, internal systems can be separated from public-facing systems, which creates an additional layer of protection. This isolation helps prevent unauthorized access to critical resources & reduces the potential for internal threats to affect the entire network.

Techniques to implement Network Segmentation

Here are some techniques commonly used to implement network segmentation:

#1. VLANs (Virtual Local Area Networks)

VLANs divide a single physical network into multiple logical networks. Devices within the same VLAN can communicate with each other – while communication between VLANs is controlled through routers or layer 3 switches. VLANs are typically based on factors such as department, function, or security requirements.

#2. Subnetting

Subnetting involves dividing a network into smaller subnetworks or subnets. Each subnet has its own range of IP addresses and can be treated as a separate segment. Routers or layer 3 switches are used to connect and control traffic between subnets.

And here is a detailed article on how VLAN and subnetting work. Feel free to visit this page.

#3. Access Control Lists (ACLs)

ACLs are sets of rules that define what network traffic is allowed or denied based on various criteria, such as source and destination IP addresses or protocols. You can control communication between different segments and restrict access to specific resources by configuring ACL.

#4. Firewalls

Firewalls act as security gateways between different network segments. They inspect incoming and outgoing network traffic based on predefined rules & policies.

#5. Software-Defined Networking (SDN)

SDN is an approach that separates the control plane from the data plane. It allows for centralized control and management of network resources through software. SDN enables dynamic and flexible segmentation by programmatically defining & controlling network flows.

#6. Zero Trust Networking

It is a security framework that assumes no inherent trust between network segments or devices. It requires authentication, authorization, and continuous monitoring for all network traffic – regardless of the network segment. Zero Trust Networking ensures that access to resources is granted on a need-to-know basis which reduces the risk of unauthorized access.

#7. Network Virtualization

Virtualization technologies, such as virtual switches and network overlays – create virtual networks on top of the physical network infrastructure. This enables the creation of isolated segments that can be dynamically managed. It simplifies the process of segmentation and enhances scalability.

It’s important to consider factors such as the organization’s specific requirements, network topology, and the level of security needed for each segment.

The chosen techniques should align with the security policies and the complexity of the network infrastructure.

Best Practices for Network Segmentation

Plan and Define Segmentation Strategy

The first step is to clearly define your goals and objectives. Determine which assets or resources need to be protected and the level of access required for each segment.

Having a clear understanding of your segmentation goals will guide your implementation strategy.

Identify Critical Assets

Identify the important assets within your network that require the highest level of protection. These could include sensitive data, intellectual property, or critical infrastructure. Prioritize the segmentation of these assets and allocate appropriate security measures to ensure their protection.

Use a layered Approach

Implement multiple layers of segmentation to enhance security. This can involve using a combination of VLANs, subnetting, IDS/IPS, firewalls, and access control lists (ACLs) to create strong protection.

Each layer adds an additional barrier and improves the overall security of the network.

Apply the Principle of Least Privilege

Only provide access permissions to devices that specifically require them for their job functions. Restrict access to sensitive segments and resources to minimize the risk of unauthorized access & potential lateral movement within the network.

Implement Strong Access Controls

Use access controls to regulate traffic between different network segments. This can include implementing firewall rules, access control lists (ACLs), or VPN tunnels.

Apply the principle of “default deny” where all traffic between segments is blocked by default and only permits necessary traffic based on predefined rules.

Regularly Monitor and Update

Continuously monitor your network segments for any unauthorized access attempts or suspicious activity. Deploy network monitoring tools to detect & respond to potential security incidents quickly.

Keep network infrastructure and security systems up to date with the latest patches to address known vulnerabilities.

Regularly Review and Update Segmentation Policies

Perform regular reviews of your segmentation policies and configurations to ensure they align with your organization’s changing security requirements. Update policies as needed and conduct periodic audits to verify that segmentation is implemented correctly.

Train Employees on Segmentation

Provide training and awareness programs for employees to understand the importance of network segmentation and their role in maintaining a secure network environment.

Educate them about security practices such as avoiding unauthorized connections between segments & reporting any suspicious activities.

Use Cases

Network segmentation has several use cases across different industries. Here are some common examples of how it is applied.

Healthcare

Hospitals often implement this network segmentation concept to protect patient data, electronic health records, pharmacy systems, and administrative networks to ensure compliance with healthcare regulations and safeguard patient privacy.

Financial Services

Banks and financial institutions use network segmentation to isolate customer transaction data and ATMs, which minimizes the risk of data breaches & financial fraud.

Industrial Control Systems (ICS)

In industries such as energy, network segmentation is important to secure operational technology (OT) networks. By separating OT systems from enterprise networks, organizations can prevent unauthorized access and protect critical infrastructure.

Guest Networks

Organizations that offer guest Wi-Fi access often employ network segmentation to separate guest traffic from internal resources. They can maintain the security and privacy of their internal systems while still offering convenient internet access to visitors.

Conclusion ✍️

I hope you found this article helpful in learning network segmentation and how to implement it. You may also be interested in learning about the best NetFlow Analyzers for your network.