What are the Benefits of Network Segmentation?

23 Dec 2020 | Randy Lindberg

What is network segmentation? The most simple definition is that it’s the process of breaking large networks into multiple segments that are isolated from each other. The multiple subnets now act as small networks on their own, allowing network administrators to control traffic flow between each of them.


Network segmentation is also referred to as network segregation, network isolation, or network partitioning. The purpose of utilizing network segmentation is to improve the security and performance of a network.


How to Segment Your Network

Controlling the flow of traffic among the various parts is how segmentation works. You may choose to prevent traffic from reaching another subnet by stopping it in a single segment. You can also limit traffic flow by type of traffic, destination, source, and many other options. How you choose to segment your network is referred to as segmentation policy.


One benefit of segmenting your network is that it yields better performance because traffic will only flow to specific parts. Network segmentation also limits an attacker's lateral movement, and this is attained by preventing the spread of any attack they do inflict. For example, malware in one section does not affect systems in other sections. Finally, the scope of compliance will also be reduced, which in turn reduces the costs affiliated with regulatory compliance.


The Electric Breaker Boxes Analogy

An electric breaker box, also called a circuit breaker box, is designed to distribute the electricity in the right amount to every outlet in every room of your home. Kicking a breaker, or blowing a fuse, is a great example of why you need network segmentation. For example, if you have a faulty lamp that blows a single fuse (kicks a single breaker), you will still have power throughout the rest of your house. This is because power is still flowing in your home. Similarly, if one subnetwork is tainted, you can shut it down so that the overall network is still operational and the other subnetworks are unaffected. The power is still flowing, but only the bad network is “blown.”


In fact, this is similar to how the power distribution grid for entire cities work. And why if the power goes out at your home, it won’t necessarily impact the power distribution grid of your entire neighborhood. You might not share the same power line or circuit as your other neighbors. It’s a brilliant segmentation of power that allows the electric companies to have less chance of a blackout because they fix single segments of the grid in the event that they fail while everyone else continues to have power “trafficked” to their home.


When it comes to an IT environment, segmentation is equally essential. It prevents the spread of threats or attacks through campus networks, data centers, or clouds. In other words, attackers cannot move to other parts of the environment with a host segment put in place. The segmentation enables containment of the threat, helping organizations to be better protected from breaches.


4 Types of Network Segmentation

Physical and virtual are the two basic methods of network segmentation. Physical is considered the most secure, but unfortunately, it’s the most expensive as well. Today segmentation has been simplified. Network traffic is grouped and tagged, which is done using access technology defined by software. The segmentation policy is then enforced on the network devices directly. With this method, you avoid the complexities of traditional approaches.


  1. VLAN or subnet network segmentation: For many organizations, segmentation is carried out by creating network segments with subnets or Virtual Local Area Networks (VLANs). With VLANs, smaller network segments are created, and all the hosts are virtually connected and appear like they are in the same Local Area Network (LAN).


On the other hand, subnets allow partitioning of networks into smaller subnets by use of IP addresses that are connected by networking devices. You will achieve efficient network performance, and the ability to contain threats from spreading if you use either of these approaches.


  1. Firewall segmentation: You can use firewalls instead of the network for enforcing segmentation. Deploying firewalls inside a data center or a network creates internal zones. The zones limit attack surfaces by segmenting functional areas. Hence, preventing the spread of threats beyond a zone.


Separating engineering applications from finance is a good example of firewall segmentation. One of the drawbacks of using a firewall is that they are costly. There are several firewall rules required to segment internal networks, and this makes them complicated. Firewalls also have a risk of misconfiguration that can break an application and potentially harm your company as a result.


  1. Segmentation with Software-defined networking (SDN): For greater network programmability and automation, SDN is often considered. Webopedia defines SDN as “an approach to using open protocols, such as OpenFlow, to apply globally aware software control at the edges of the network to access network switches and routers that typically would use closed and proprietary firmware.” The benefits of using it are automated load balancing, a streamlined physical infrastructure, the ability to scale network resources, and on-demand provisioning. 


  1. Micro-segmentation: Network World defines microsegmentation as “a method of creating secure zones in data centers and cloud deployments that allows companies to isolate workloads from one another and secure them individually.” The approach uses whitelist models that block all unpermitted traffic, and is typically done in software.


How to Test Network Segmentation

How can you test if your network segmentation strategies are working to prevent a breach? The best way is to bring in a professional. While there are vulnerability assessments and penetration tests you or your IT team can do internally, we highly recommend bringing in a third party to perform an IT audit and provide your organization with a thorough risk assessment. 


Get a Network Penetration Test from Rivial Security today.