What is Network Segmentation? Implementation and Benefits

The invisible boundary separating the outside world from the data essential to an enterprise's operations, the network perimeter, was formerly the focus of network architects' security plans. People inside the cordon were thought to be trustworthy and non-threats. They faced few limitations on their access to information as a result.

 

The trust presumption has been put into doubt by recent high-profile breaches. For starters, insiders can in fact cause breaches, mostly unintentionally but occasionally on purpose. Additionally, when attackers breach the perimeter, they have unrestricted access to almost any data, application, asset, or service by moving laterally throughout the network (DAAS).

 

Attackers may readily ex filtrate a wide range of valuable assets with nearly unrestricted access, frequently before the breach is even noticed. Network segmentation comes into the picture now. Network designers may create a micro perimeter via segmentation, basically creating a second line of defense, surrounding the protected surface. 

 

Virtual firewalls may sometimes automate security provisioning to make segmenting operations easier. Regardless of how it is done, only authorized users are allowed access to the assets within the protected surface while everyone else is by default denied.

 

For attackers, segmentation spells bad news because, unlike in the days of presumed faith, breaching the perimeter does no longer obtain access to sensitive data. Physical or virtual micro perimeter stop threats from lateral movement inside the network, effectively invalidating much of the work that went into causing the original breach.

 

Also Read | Network Security: Types, Advantages and Disadvantages

 

What Is Network Segmentation?

 

Network segmentation is an architectural strategy that separates a network into several segments or subnets, each of which functions as a separate little network.
 

In this way, granular rules may be used by network administrators to regulate the movement of traffic between subnets. Organizations utilize segmentation to strengthen security, increase performance, improve monitoring, and localize technical problems.

 

The "crown jewels" of the business, such as customer personal information, corporate financial records, and highly confidential intellectual property, are protected by network segmentation, a powerful tool used by network security personnel to stop unauthorized users, whether curious insiders or malicious attackers.

 

These assets are now routinely dispersed over hybrid and multi-cloud settings, including software-defined networks (SDNs), private clouds, and public clouds, all of which must be protected from threats. It is first required to think about the idea of trust in network security in order to comprehend the security applications of network segmentation.

 

How does Network Segmentation Work?

 

A network is divided into several zones via network segmentation, and each zone or segment is independently managed. To regulate what traffic is permitted to travel through the segment and what is not, traffic protocols must be used. In order to handle security and compliance, it also covers security protocols for each zone.

 

Dedicated hardware is used to create network segments that are walled off from one another and only permit users with the proper credentials to access the system. Network configurations provide rules that specify how users, services, and devices on subnetworks can communicate with one another.

 

Differences between Network Segmentation and Micro-segmentation

 

Network segmentation should not be confused with micro-segmentation, which lowers an organization's network attack surface by implementing certain security policies to restrict east-west connectivity at the workload level. 

 

Despite having certain uses, micro-segmentation should not be confused with traditional network segmentation. There are several differences between network segmentation and micro-segmentation, including the following:

 

1. A bigger portion of the network is covered by conventional network segmentation. The usage of micro-segmentation at the device level makes it ideal for the internet of things (IoT) and edge devices.

 

2. Using network segmentation with a physical network is effective. Virtual networks use micro-segmentation.

 

3. Policies for network segmentation are extensive. Policies for micro-segmentation are significantly more precise.

 

4. Hardware is the basis for network segmentation. Software is generally used for micro-segmentation.

 

5. North-South traffic is restricted at the network level via network segmentation. At the workload level, micro-segmentation restricts east-west flow.

 

Also Read | Zero Trust Explained- Meaning, Foundation and Advantages

 

Best Practices of Network Segmentation

 

When first starting out, a lot of firms over-segment their networks. As a result, management may become less visible across your whole network and more challenging than it was before segmentation. It's also crucial to avoid under-segmenting your network, as doing so maintains your attack surface open and weakens your security posture.

 

Network segmentation is a great technique to increase network security, but it only works when you regularly verify to make sure that vulnerabilities are patched, access is restricted, and updates are applied.

 

The most important thing is that segment auditing makes sure there are no exploitable coverage gaps and that any network risks are minimized, putting you one step ahead of persistent bad actors.

 

In terms of network segmentation, least-privileged access is just as important as it is for access control generally. You may reassure your users, network administrators, and security team that access will only be allowed when necessary by implementing the least privilege concept across all of your network segments.

 

Access to third-party users already has a significant level of risk, so it's crucial to only provide it where it's required, especially if you're offering it to a number of different network segments. 

 

Segmentation lowers the overall risk to your network, but it does not imply you should start granting access to outside parties without first assessing how that can influence your network security posture.

 

By segmenting your network, your business has a wide range of helpful automation alternatives. Automating network segmentation enables you to swiftly detect and categorize new assets and data, which is another segmentation best practice in and of itself. This is besides the benefits of automation in general, such as enhanced visibility, decreased MTTR, and improved security.

 

Implementation of Network Segmentation

 

Network segmentation divides a bigger network into several, independent segments, each with its own set of security guidelines. These segments store particular endpoint or application types with the same degree of confidence.

 

The implementation of network segmentation can be done by:

 

1. Physical Segmentation

 

Physical segmentation entails dividing a bigger network into a number of smaller subnets, as the name suggests. The subnet gateway, which regulates which traffic enters and leaves, is often a physical or virtual firewall. Because the topology is set in the design, physical segmentation is very simple to manage.

 

2. Logical Segmentation

 

Network addressing systems or virtual local area networks (VLANs) are the two main techniques used by logical segmentation to establish subnets. Because traffic is automatically routed to the correct subnet using VLAN tags, VLAN-based systems are relatively simple to install. 

 

In-depth knowledge of networking theory is necessary for network addressing strategies to be equally successful. Because logical segmentation doesn't involve any wiring or actual physical movement of components, it is more versatile than physical segmentation. Configuring subnets may be made much easier by automated provisioning.

 

Simplifying the maintenance of firewall policies is possible by switching to a segmentation design. Use of a single consolidated policy for threat detection and mitigation, threat mitigation, and subnet access control is an emerging best practice as opposed to dispersing these tasks throughout the network. By using this strategy, the organization's security posture is strengthened and the attack surface is decreased.

 

3. Perimeter-based segmentation

 

Perimeter-based segmentation divides the world into internal and exterior areas depending on what can be trusted; anything outside the network segment cannot be trusted. 

 

Because of this, internal resources are often unrestricted and run across a flat network with little internal network segmentation. The network's fixed nodes are where filtering and segmentation take place.

 

The original purpose of VLANs was to separate broadcast domains in order to enhance network performance. VLANs were never intended to be used as security tools, but they have evolved over time to be utilized in this capacity. VLANs have a very broad degree of access, which is problematic because there is no intra-VLAN filtering.

 

Additionally, a policy is required in order to transition between segments. With policies, you may either limit traffic or block it from moving from one section to another (based on the traffic type, source, and destination). 

 

For perimeter-based segmentation, the network firewall is a frequently used technique. Initially, it was used to regulate the north-south flow of network traffic while allowing any-to-any communication inside a segment.

 

4. Network Virtualization

 

In the modern day, several firms maintain a number of network zones with specialized functions that necessitate segmentation at various network points. Furthermore, the variety of endpoint types that the network must handle has increased, each with a different level of trust.

 

Because of this, perimeter-based segmentation is no longer adequate. The perimeter is increasingly hazy with no distinct lines of demarcation because of developments like cloud computing, BYOD, and mobile. 

 

To improve security and network speed, we now need segmentation that is deeper into the network. More network segmentation is furthermore required due to the east-west traffic patterns of today. Network virtualization can be useful in this situation since it advances segmentation.

 

The provision of network and security services that are independent of the physical infrastructure is the essence of network virtualization. Network virtualization plays a crucial role in promoting effective network segmentation by enabling network segmentation throughout the whole network, not only at the perimeter. 

 

The perimeter-based segmentation we were accustomed to in the past has effectively been virtualized and disseminated down to each and every segment in the network, coupled with flexible, fine-grained security settings.

 

Benefits of Network Segmentation

 

Network segmentation gives each sector of the network its own security services, giving the user more control over network traffic, enhancing network performance, and enhancing security posture.

 

1. Better security comes first. Everyone is aware that your security is only as strong as its weakest link. Unavoidably, a huge flat network exposes a substantial attack surface. 

 

2. The isolation of network traffic within the smaller sub-networks, however, limits the attack surface and prevents lateral movement when a big network is divided into smaller sub-networks. 

 

3. As a result, even if the network perimeter is penetrated, attackers cannot move laterally through the network due to network segmentation.

 

4. Segmentation also offers a logical means of isolating an active assault prior to it spreading throughout the network. Segmentation, for instance, guarantees that malware in one section does not harm systems in another.

 

5. By breaking an assault up into parts, the attack surface is minimized to the bare minimum.

 

6. Let's move on to performance now. By eliminating unneeded traffic in a specific area, segmentation minimizes network congestion and enhances network performance. For instance, a hospital's medical gadgets can be segregated from its visitor network so that visitor web surfing traffic won't impact them.

 

7. Because of network segmentation, we have fewer hosts per subnetwork, less local traffic in each subnetwork, and only allow the prescribed amount of external traffic in each subnetwork.

 

The practice of network segmentation is now more of a recommendation than a requirement. After all, trends in businesses that are vulnerable to cybercrime, like the Electronic Payment Business, suggest that segmentation may become a necessary safety strategy. 

 

Regardless of whether or not that happens, the fierce competition for nodes in some of the most competitive industries raises concerns about the welfare policies of network segmentation.