What Is Network Segmentation?

Instasafe

Sep 14, 2023 • 8 min read

What Is Network Segmentation?

Network segmentation is a term used to define the network security strategy used by businesses of all sizes. The network segmentation process divides the whole network into multiple segments or subnet networks, each working as an individual network.

The individual network or smaller subnet provides enhanced traffic control into that particular segment, increasing security.

Basically, it is a process of creating a smaller network within the extensive network. That's why it is also called network segregation or network isolation. By using network segmentation, businesses can limit the traffic into segments based on location. The traffic can also be restricted based on the source, destination and type.

With network segmentation, organisations can prevent access to their valuable resources such as financial records, intellectual property and more for unauthorised users. This way, organisations can create a safer and more efficient network that boosts performance and improves monitoring.

How Does Network Segmentation Work?

Network segmentation involves dissecting or dividing the whole network traffic into multiple segments or subnets.

Each segment or subnet has its distinct address range. A definite set of traffic protocols for each segment manages what kind of traffic passes and whatnot. Further, each segment's security policy and requirements can differ based on the need.

In network segmentation, devices on one subnet cannot directly communicate or connect with devices on another subnet. Devices must go through a gateway device or router connecting the two subnets to communicate.

Network segmentation is usually employed with security approaches like firewalls to create a more secure network. It has dedicated hardware to wall or protect each subnet, and only users with credentials can access the particular subnets, which makes it difficult for attackers to bypass the security protocols.

Further, there are certain sets of rules around each subnet and network to determine how subnetworks, devices, etc, can interconnect with each other.

The isolation of each network in the network segmentation process makes it challenging for attackers to access network-sensitive data.

What are the Benefits of Network Segmentation?

Network segmentation offers various prominent benefits to all kinds of businesses. Some of the listed benefits are:

Enhanced Access Control - The first benefit of network segmentation is enhanced access control. In network segmentation, only approved users can access the resources in the network.

With specific user permission for data access, users can enter the network and only access the resources needed for the job. Organisations can limit access to sensitive data in network segmentation, which prevents insider attacks.

Better Network Performance - Another benefit of network segmentation is better network performance. There would be less congestion since there are only a limited number of connected devices in each network segment or subnet.

The reduced traffic in each subnet would help control the network, allowing efficient and faster performance.

Fewer Access Points - Organisations generally store their sensitive data within one of the network segments. In extensive networks, users can enter and leave the network anytime and access any data, creating a risk of data leakage.

However, with network segmentation, there are only a few access points for accessing protected or sensitive data, which minimises the risk of data theft.

Improved Threat Management - Generally, every network has a firewall, so an outsider without access can't breach the network wall, but hackers can easily break the firewall.

However, in network segmentation, there is a separate firewall in the network segment, which means it has a firewall within the firewall.

This level of security makes it impossible for hackers to breach the segment. Even if he has entered the main network, then to access the sub-network, he needs to bypass the security protocols of that particular network segment.

Better network monitoring - Since the network segment is divided into smaller segments, this removes the network congestion and provides enhanced visibility within the network.

It allows security managers to monitor the activities of users within the network. Security managers can take the appropriate action in case of any suspicious behaviour or pattern.

Types of Network Segmentation

There are two types of network segmentation which are:

Physical segmentation - In physical segmentation, the network is divided into multiple physical locations and subnets. Dedicated hardware is used to build these physical locations and subnets. This is the most used approach, but managing a physical segmentation is complex.

Since in this perimeter-based network, every segment has its own firewall, switches, internet connection and more, it is quite expensive. Furthermore, physical segmentation generally works on trust, which means those inside the network perimeter are trustworthy, and those outside perimeters are not. This kind of approach leaves room for breach. If a hacker somehow bypasses the physical segmentation network firewall, he can freely access the resources within the network.

Virtual or Logical Segmentation - Virtual or logical network segmentation covers the entire network using the Virtual Local Area Network (VLAN). VLANs are generally employed to improve the network performance. In virtual segmentation, an organisation doesn't need to invest in hardware like wires, switches, etc., making it a cost-effective technique.

In virtual segmentation, perimeter-based or physical infrastructure is deployed using other network addressing schemes or VLANs. The work of VLANs is to send assigned or appropriate traffic into subnets, which makes the whole network traffic more secure.

Use Cases of Network Segmentation

Let's understand, through use cases, how network segmentation can be employed in business.

To prevent internal data leakage or breaches, companies can create subnets and segments for every department, such as the developer team has a specific network segment or the quality assurance team has a different segment.

So, if a developer team member tries to access data or resources from the quality assurance department, the administrator will receive an alert. Then, the administrator or IT department will try to learn if it's because of an accident or any data stealing attempt.

Another use case of network segmentation is in hotels and lodges where owners provide free Wi-Fi access to their customers.

While providing access to the hotel Wi-Fi, guests only have access to particular segments that connect them to web services.

Further, e-commerce store owners can store sensitive information and data, such as card details, etc, from their customers in isolated or private network segments.

Only authorised persons have access to this segment. In case of any attempt from an unauthorised person to access the resource, the network denies the request immediately.

How to Implement Network Segmentation and Best Practices

The process of implementing network segmentation requires proper planning and effort. The following steps need to be taken while implementing network segmentation such as:

Do Regular Inventory - The first step of implementing network segmentation is to thoroughly do an inventory of business IT systems. Organisations need to know about their IT systems and where the sensitive information is stored. Not just this, it is also essential to be aware of who has access to sensitive data and all.
Define User Base - After doing the inventory, businesses must define the user base based on rules for accessing the data and information.
Check Network Bandwidth - Not just this, some applications on the network consume most of the network capacity and end up slowing down the whole network. By identifying that, an organisation can put that application on the subnet to restore the natural bandwidth of the network.
Create a Segmented Network - After knowing all about the sensitive data, user base and network bandwidth, it is time to segment the network. Segmentation should be done based on the job role or user's resource access.
Initiate with Easy Segment - To keep an eye on every network segment, administrators need to learn about the network segment process, too. They can start practising with an easy and less complicated segment.
Set Default Deny Rule - One of the critical parts of network segmentation is setting rules. So, it is best to set a default deny rule so nobody can access the network until the authentication process is done.
Do Modifications Frequently - After setting or defining the network segment configuration, it is essential to check them regularly and make modifications if needed.
Continuous Monitoring - Lastly, continuous monitoring is essential in network segmentation to ensure everything is fine. Administrators can alert the IT department if they notice unusual traffic and bad-behaving apps.

Some of the best practices that needed to be included for effective network segmentation:

Apply Least Privilege - One of the best practices to adopt in network segmentation is least privileged access. That way, access will only be granted to users, administrators and security managers when necessary. The principle of least privilege will be set to all network subsets and segments. One of the modern security solutions, ZTNA, works on the least privilege model.
Limit Third-Party Access - Accessing third-party applications on every network segment will open your network to risk and vulnerability. So, it's best to limit the access of third-party applications to network segments.
Automate - Automating the network segmentation task helps in performing tasks quickly. Further, it can also help in identifying the data and assets.
Avoid Over-Segmentation - While network segmentation is essential for security reasons, avoid over-segmenting. It can decrease the network visibility, and managing a segment can become tricky.

What are the Network Segmentation Limitations?

Traditional network segmentation has some shortcomings in today's environment, such as:

Poor Performance - Traditional network segmentation leads to poor performance since more network devices, such as routers, firewalls, etc., burden the network and decrease its performance.
Difficult Controls - Further, with the traditional network segmentation approach, defining the access control for remote workers, contractors, and more is difficult. This approach lacks a fine-grained control mechanism.
Scalability Problems - Another major issue with traditional network segmentation is its inability to handle the workload. If, at some point, the business wants to scale, then they need to upgrade the network, resulting in high cost.
Complex Management - Management in traditional network segmentation is a complex process. Every new application or device in network segmentation asks for updating firewall rules, so the whole process becomes taxing.
Default Trust - One of the biggest concerns in traditional network management approaches is explicit default trust to those inside the network, which creates room for insider attacks.
Misconfigurations - Some of the applications employed in network segmentation, such as VLANs, etc, are easy to misconfigured, which creates a risk of attacks and breaches.

Why is ZTNA Better than Traditional Network Segmentation?

In today's landscape, where organisations are allowing remote work and everybody is relying on the cloud, security is the biggest concern among organisations. Network segmentation might seem a good option for business, but its limitations can not be overlooked.

However, Zero Trust Network Access is far better than traditional network segmentation. It is a modern solution designed for the modern user base.

The ZTNA model and framework works on zero implicit trust, which means access can't be granted to anyone. Further, the access policies on the ZTNA model work on the least privilege basis, depending on the context and identity.

The ZTNA infrastructure removes lateral movement in the network by connecting users directly to resources or applications. Users can access resources or applications they need to do their job. So ZTNA does establish network segmentation but more securely and efficiently.

Some of the prominent benefits of using the ZTNA framework over traditional network segmentation are:

It offers secure application access to external users from unmanaged devices while keeping them away from the network.
ZTNA framework can be deployed on the software on-premise and cloud devices, making it scalable and flexible.
Further, it removes the implicit trust-based access with identity-based trust.

InstaSafe and Network Segmentation

Network segmentation is an essential part of network security, and InstaSafe Zero Trust Solution can be used to set up and improve network segmentation in a business's IT system. The ZTNA solutions by InstaSafe are based on a "never trust, always verify" approach.

One can set up safe network links and connections between users and the tools they need to get to with InstaSafe ZTNA. This method works well with network segmentation because it strictly controls access, ensuring that users only go to the parts of the network they are allowed to.

InstaSafe helps enterprises create fine-grained security policies for network segments through micro-segmentation.

Frequently Asked Questions

What is the difference between network segmentation and micro-segmentation?

Network segmentation is breaking down large networks into smaller segments to control the network better.

While micro-segmentation takes the network segmentation process further by dividing a network into smaller segments, often on a per-application or per-workload basis, each application, system, or individual device can be placed in its micro-segment.

2. Who needs to implement network segmentation?

Network segmentation is not limited to a specific type or size of organisation; instead, it is relevant for any entity that wants to enhance its network security and reduce the potential impact of security breaches.

3. Why is network segmentation used?