What is network segmentation: Understanding the basics

Network segmentation is a security technique that divides a large network into smaller sub-networks or segments. This security technique enhances network performance, improves network security, and facilitates network management. Many IT experts understand the benefits of isolating different parts of a network, but it seems that few organizations have actually fully implemented the practice. We will explore the basics of network segmentation and its importance in this blog.

Brief explanation of network segmentation

Network segmentation means dividing a network into smaller segments or sub-networks. They each have their own security and performance characteristics. This technique allows for more granular control over a network. It also helps to minimize the impact of security breaches and other network disruptions.

Importance of network segmentation

Network security is of the utmost importance in today’s digital world. It’s essential to have a cybersecurity strategy in place because of the increase of connected devices and the rise of cyber attacks. Network security reduces the attack surface and minimizes the impact of a security breach. It’s easier to monitor, control and manage network traffic by dividing a network into smaller segments. This improves the overall performance and stability of the network. Network segmentation also allows for better scalability and management of network resources. This makes managing and maintaining network infrastructure easier.Network segmentation is a crucial part of network security and management. Organizations can improve their network security by understanding the importance and basics of network segmentation. This way, they can enhance their performance and better manage their network resources.

What is Network Segmentation?

Each of the segments created with network segmentation is isolated from the rest, allowing for more granular control over network traffic and security. This helps to minimize the impact of security breaches, network failures, and other disruptions.

Definition and explanation of network segmentation

Network segmentation is dividing a large network into smaller segments or sub-networks with their own security and performance characteristics. This improves the security and performance of the network. Network segmentation makes it easier to manage and maintain a network. Routers, firewalls, and other networking devices are used to isolate different segments of the network.

Types of network segmentation (physical, logical)

There are two main types of network segmentation: physical and logical. Physical network segmentation means physically dividing different segments of the network into separate parts of a building or different buildings. Logical network segmentation means logically dividing a network using software and hardware, even if everything is located in the same physical space.While physical network segmentation is typically used in larger organizations with multiple physical locations, logical network segmentation is used in smaller organizations or in situations where physical separation is not practical. Logical network segmentation is typically easier and faster to implement.Network segmentation is important to improve the security and performance of modern networks. It’s easier to monitor, control, and manage network traffic when you divide a network into smaller segments. This improves the overall stability and security of the network.

Network segmentation vs. micro-segmentation

When it comes to network security, both network segmentation and micro-segmentation policies should be implemented. Network segmentation focuses on limiting north-south traffic between different networks, while micro-segmentation provides east-west protection within a network. Which means restricting access to all devices, servers, and applications that communicate with each other. Micro-segmentation is a more granular approach for intra-network traffic. While network segmentation can be seen as an overarching security policy for the entire infrastructure.

Why is network segmentation important?

Network segmentation can be a chore to set up, that’s why many businesses might not have set it up for their network. It requires detailed information about the network’s infrastructure, strong security controls, and major reworks to the network architecture and the business processes. This way, segments can be created without leaving any gaps. Implementing network segmentation isn’t always easy, but it is a critical aspect of modern network design and management. The benefits of network segmentation massively outweigh the challenges. It improves network security, enhances network performance, and facilitates network management.

Improving network security

The primary benefit of network segmentation is improved security. Dividing a network into smaller segments reduces the attack surface and minimizes the impact of a security breach. Strong network segmentation can help keep attackers from breaking out of a system before the breach is contained and their access is cut off. This minimizes the damage caused by a breach.It can also buy you extra time during an attack. An attacker might be able to break into a segmented portion of the network but it will take longer or it might even be impossible to get access to the whole network. Network segmentation makes it easier to protect your most sensitive data. It creates a layer of separation between servers with sensitive data and everything outside the network. This reduces your risk of data loss or theft.Each segment can be monitored and controlled separately, which makes it easier to identify and contain insider threats as well as outsider threats. Strong network segmentation makes it easier to implement and enforce security policies, like firewalls, access control lists, and encryption to protect your most sensitive data.

Enhancing network performance

Another important benefit of network segmentation is improved network performance. Dividing a network into smaller segments makes it possible to isolate heavy traffic from other parts of the network. This improves the overall performance and stability of the network because it reduces the number of hosts and users within a segment. It also makes managing network resources and allocating bandwidth easier, further improving network performance.

Facilitating network management

Network segmentation makes it easier to manage and maintain network infrastructure. Dividing a network into smaller segments makes it possible to isolate different parts of the network and manage them separately, reducing the risk of network disruptions. Network segmentation also makes it easier to manage and allocate resources like bandwidth and processing power. This improves the overall efficiency and scalability of the network.In conclusion, organizations can better monitor, control, and manage network traffic, improving the overall security and stability of their network.

How Does Network Segmentation Work?

Next, we will explore the steps involved in network segmentation and the role of VLANs, routers, and firewalls.

Steps involved in network segmentation

The steps involved in network segmentation include:

1. Define the network segments: The first step in network segmentation is defining the different segments of the network, taking into account factors such as performance, security, and management requirements.
2. Determining the network topology: The next step is to determine the network topology, which will help to ensure that network segmentation is implemented in a way that meets the specific needs of the organization. With network topology we mean the physical and logical arrangement of nodes and connections in the network. Nodes can be switches, routers, and software with switch and router features.
3. Create the segments: The next step is to create the segments using network technologies such as VLANs, routers, firewalls, and more. Choose the right tools, taking into account factors such as cost, scalability, and performance.
4. Configure the segments: The next step is configuring the segments to ensure that they are properly isolated from each other and that performance and security requirements are met.
5. Monitor and maintain the segments: The last step is monitoring and maintaining the segments to ensure that they continue to meet performance, security, and management requirements.

The role of routers, VLAN segmentation, segmentation controls, SDN segmentation, and DMZs

There are multiple ways to segment your network. Usually, segmentation is done through a combination of firewalls, Virtual Local Area Networks (VLANs), and Software Defined Networking (SDN).

Routers

The next important technology in network segmentation is routers. They help to route traffic between the different segments of the network. Routers use routing tables to determine the best path for network traffic. They can also be configured to enforce security policies and limit the flow of traffic between segments.

VLAN segmentation

The VLAN or Virtual Local Area Network is an important technology that can be used to segment networks. They allow multiple network segments to exist on the same network, but logically separated from each other. VLANs are created by tagging network traffic, which helps to isolate different segments of the network. Although this approach effectively segments the network, they are often complex to maintain and often require comprehensive re-architecting.

Segmentation controls

A segmentation control is any device, process, or system that is used to create network segments to isolate assets on the network.Segmentation controls need to be tested to verify their efficacy against cyber attacks. These tests check how well segmentation controls are isolating different network zones and they are often carried out during larger pentests. This way, organizations can verify if their network segmentation meets critical security standards.

Firewalls

Firewalls play an important role in network security and network segmentation because they can be used to filter traffic between two separate nodes on a network. They help to protect network segments from external threats, by controlling and monitoring network traffic. Firewall can allow or block specific types of network traffic and they can be used to enforce security policies and to prevent unauthorized access to network segments. Firewall functionality in the cloud is also called FWaaS or Firewall as a Service. This can have financial, network performance, and security benefits.

Access Control List (ACL)

Another network segmentation control is the Access Control List (ACL). ACLs are permissions attached to an object on the network. These permissions specify who can access and use the object and what the object is allowed to do. ACLs can be restrictive but also very effective.

SDN segmentation

SDN segmentation or Software-Defined Network segmentation isolates internal network traffic with the help of software-defined network segments and predefined rules. It’s basically network segmentation without the need for infrastructure change. SDN segmentation means creating security policies around individual or logically grouped applications, regardless of their physical location. It’s a more modern approach to network segmentation that applies an SDN-automated network overlay. A network overlay is a network on top of another network, which removes the hardcoded constraints of a physical network. This approach is complex and has to be implemented correctly for successful micro-segmentation.In conclusion, network segmentation can be achieved through these technologies. By understanding how these technologies work, organizations can better plan and implement network segmentation strategies that meet their specific needs.

DMZs

DMZ stands for demilitarized zone in network security. It can be a physical or logical subnet (segment) that separates a LAN or Local Area Network from other untrusted networks. Usually, this means that it’s separated from the public network. DMZs are also called perimeter networks because they are defined by two strict segmented boundaries. One boundary between the DMZ and the untrusted outside network and another one between the DMZ and the internal network. Usually, these boundaries are firewalls that isolate the business resources from the internal network and from the outside untrusted networks.

Implementing Network Segmentation

It’s important to implement network segmentation properly in order to achieve the desired benefits when it comes to network design and management. We will explore best practices for network segmentation, the available tools, and the factors to consider for the implementation.

Network segmentation best practices

It’s important to follow best practices in order to achieve the desired results when implementing network segmentation. Some best practices for network segmentation include:

1. Follow the principle of least privilege: The principle of least privilege is one of the most important principles of zero trust. This involves denying network access at every level and it requires all parties to provide authentication and verification before gaining access to other parts of the network. It’s important to minimize who and what has access according to their actual need. This means, not everyone needs access to every part of the network. By following the principle of least privilege, you can limit hosts, services, users, and networks from accessing data and functions outside of their immediate responsibility. Only users with the right permissions can access the data within that network. Through zero-trust architecture, network administrators can identify bad actors or unauthorized parties attempting to infiltrate the systems. This strengthens the overall network security and makes it easier to monitor and track traffic throughout the network.
2. Limit third-party access points: It’s also important to limit third-party access to your network to minimize exploitable entry points. Giving too much third-party remote access remains a key vulnerability for organizations. It’s important to assess the security and privacy practices of the third parties and ensure that they have just enough access to perform their designated responsibilities and nothing more. Third parties can be isolated by creating unique portals with customized access controls for every party.
3. Continually audit and monitor your network: Throughout the segmentation process there should be constant monitoring of network traffic and network performance to ensure the architecture is secure and that there are no gaps or vulnerabilities. This way, you can quickly identify and isolate traffic and security issues. Regular audits and penetration testing to surface architectural weaknesses are also important. This allows organizations to reevaluate the effectiveness of their current security policies and adjust them. Audits and monitoring are also especially important when your business is growing and your network architecture may no longer meet your needs. This can help you adjust your network segmentation design to your new needs, optimal performance and security.
4. Visualize your network: To design effective and secure network architecture, you first need to understand why your users are, what components make up your network, and how all the systems relate to each other. It would be difficult to plan and achieve your desired state without a clear picture of your current state. Identify who needs access to what data so you can map your network successfully.
5. Create Easier Legitimate Data Paths: You should evaluate and plan your architecture design around the paths users will take to connect to your network. It’s important to create secure access points for your users but you should also pay attention to how bad actors might try to access those same segments illegitimately. Legitimate paths should be easier to navigate than illegitimate paths in order to make your security better. For example, when you have firewalls sitting between your vendors and the data they need to access, only some of these firewalls are able to block bad actors. This means you will need to rethink your architecture.
6. Identify & Label Asset Values: Before you start any network segmentation process, you should take stock of your assets and assign values to them. These assets should be organized by their importance level and data sensitivity. An asset can be anything from an IoT (Internet of Things) device to a database. Separating these assets of lower and higher value while maintaining a comprehensive list of company assets allows for an easier transition and implementation of a network segmentation strategy.
7. Combine similar network resources: After the inventory of your assets has been documented, you should start to group together similar network resources into individual databases. This will save time and reduce security overhead. Categorizing data by type and degree of sensitivity allows you to quickly apply security policies while protecting your data more efficiently. This practice also makes it easier to identify which networks have prioritization over others. This makes network monitoring and filtering more accessible.
8. Don’t over or under-segment your network: A common mistake when implementing network segmentation is over-segmenting a network or under-segmenting a network into too few segments. Organizations often wrongly assume that segmenting as much as possible creates the highest level of security. You should have enough resources to control and monitor multiple networks without impacting employee productivity. Over-segmentation causes employees to go through multiple access points to gain access to data. This creates workflow inefficiencies and restricts traffic flow. It can also create more vulnerabilities because it takes longer to implement security updates for each individual network. Too many segments add unnecessary complexity, make it harder to manage the whole network, and increase the risk of making mistakes. On the other hand, under-segmenting can also prove ineffective if there is not enough separation between each system.
9. Implement Endpoint Security & Protection: Endpoint devices are often targeted by cyber attack because they are often unsecured and lack proper protection. One hacked device can create an entry point for hackers to enter the entire network. Technology like endpoint detection and response (EDR) allows organizations to provide an extra layer of security by proactively monitoring indicators of attacks and indicators of compromise.

Choosing the right tools for network segmentation

There are many tools available for network segmentation. We will divide them into two groups, the hardware-based solutions and the software-based solutions. Examples of hardware-based solutions are routers, firewalls, and switches. Software-based solutions include VLANs and network access control (NAC). It’s important to consider factors such as cost, scalability, performance, and ease of use when choosing your tools for network segmentation.In the past, multiple VPNs were used to segment networks and secure access to sensitive systems. This introduces a bunch of problems like:

• Scalability: Using VPNs you end up becoming more permissive to keep the rules list to a manageable size.
• Performance impact: VPNs add complexity to networks and this can increase latency and impact application performance.
• Insufficient audit trails: There aren’t enough details about who performed each query or command, only that a session has occurred.

Factors to consider when implementing network segmentation

There are several factors that need to be considered when implementing network segmentation, including:

1. Network size and complexity: It’s important to know the size and complexity of a network to determine the tools and techniques that are best suited for network segmentation.
2. Security requirements: Security requirements will determine the types of network segments that need to be created and the security policies that need to be implemented.
3. Performance requirements: It’s important to know the exact performance requirements because they will determine the types of network segments that need to be created and the types of tools that need to be used to manage network traffic.
4. Network management requirements: Network management requirements will determine the types of tools that need to be used to manage and maintain the network segments.

Network segmentation is a critical aspect of network design and management, so it’s important to implement it properly to achieve the desired results. Organizations can implement network segmentation strategies that meet their needs by following best practices, choosing the right tools, and considering the factors involved in network segmentation.

Conclusion

We have now discussed the importance of network segmentation and its benefits for organizations.

Recap of key points

To recap, we have discussed the following key points:

• The importance of network segmentation
• The benefits of network segmentation: enhanced security, improved network performance, and simplified network management
• Different approaches to network segmentation: VLAN segmentation, routers, segmentation controls, DMZs, and SDN segmentation

Future outlook for network segmentation

Network segmentation is only going to become more important as the threats in the digital landscape continue to evolve. Organizations need to make sure their networks are secure and protected from potential attacks as they’re becoming increasingly reliant on technology.

Final thoughts and recommendations

In conclusion, network segmentation is an essential aspect of network security that should not be overlooked. Organizations can enhance security, improve network performance, and simplify network management by dividing their network into segments.You should conduct regular security assessments and adopt the latest network segmentation techniques to stay ahead of evolving threats.

Jimber solutions

Network Isolation

An attacker can easily breach an organization’s network perimeter and gain access to local network resources. Hackers can still get into the segments created on the corporate network.Our Network Isolation ensures secure access to corporate networks by constantly authenticating every user and device. Not trusting anything and verifying everything provides better security and micro-segmentation. Users only have access to applications, data and devices that are explicitly defined by their perimeters rather than full access to the network. You no longer need to rely on expensive hardware thanks to this network segmentation on a software level. The micro-segmentation also reduces the places threats can move to and attack from.Finally, Network Isolation makes day-to-day administration easier. Instead of having to perform complex network segmentation, organizations can easily segment their network themselves. One of the components of Network Isolation is our Network Isolation Portal. You can see all application activity and further fine-tune your network.