What is Network Segmentation?

4 mins

What is Network Segmentation? Put simply, network segmentation is a cybersecurity strat...

What is Network Segmentation?


Put simply, network segmentation is a cybersecurity strategy that involves dividing a large network into smaller, isolated segments or subnets.

As cybersecurity increasingly becomes a concern to organisations in today's hyper-connected world – with cyber threats becoming more and more sophisticated and prevalent – network segmentation is a robust method of protecting company data. By having each subnet act as a self-contained network with its own set of rules, it controls how traffic flows between the subnets, allowing you to limit the flow or stop it completely, preventing data from one part from reaching another. Doing so can prevent – or at least limit – lateral movement of threats across your wider network, reducing the potential damage that an attack might do, since hackers would have to breach barriers between subnets.

What are the benefits of Network Segmentation?

Network segmentation is gaining prominence as a measure against cybercrime for a number of reasons, namely the benefits to organisations in terms of helping to strengthen their cybersecurity position. Since the primary purpose of network segmentation is to enhance security, companies that can implement this strategy are leading the charge in the fight back against cybercrime.

Isolating subnets limits the spread of threats by keeping the rest of the network secure if one segment is compromised. What’s more, as attackers often target specific vulnerabilities within a network, segmentation isolates critical assets, minimises the attack surface and makes it difficult for attackers to find high-value targets.

Segmentation can also enhance performance by reducing congestion – ensuring that mission-critical applications receive the necessary bandwidth – and allowing for easier monitoring and troubleshooting. Optimised traffic flow allows for better network management, while smaller segments mean that any issues that arise are simpler to pinpoint and resolve, reducing downtime.

How do you implement Network Segmentation?

Organisations can start implementing network segmentation effectively by identifying and categorising their network assets, determining which assets are critical to their operations and must be protected at all costs. From there a range of technologies exist for segmentations including VLANs (Virtual Local Area Networks), internal firewalls and SDN (software-defined networking), which enables the network to be centrally controlled. It’s also important that a clear set of network policies are defined, including what resources are accessible within each segment, and who should have access to them. By ensuring a robust system of controls and authentication mechanisms, and that only authorized personnel can access specific segments, organisations can maximise the effectiveness of their segmentation.

What are Network Segmentation best practices?

Regularly auditing and reviewing your segmentation strategy will ensure that it aligns with your organisation's evolving needs and security threats. Among other best practices, it is advisable to only grant users access to the resources they need to perform their roles, to avoid unnecessary security risks. You should also educate your employees about the importance of network security and their role in maintaining it, as this can help prevent accidental breaches.

 Meanwhile, be sure to:

  • use monitoring tools and anomaly detection mechanisms to keep an eye on segment traffic, taking immediate action against any unusual or suspicious activity.
  • take a proactive approach to addressing vulnerabilities by conducting penetration tests which will identify weaknesses in your segmentation strategy.
  • and develop a comprehensive incident response plan that outlines the steps to take in the event of a breach, including procedures for isolating compromised segments.

In summary, the strategy of dividing your network into smaller, isolated segments is a powerful one for boosting your organisation's defences against cyber threats. Network segmentation allows you to limit the lateral movement of attackers and reduce the potential impact of breaches. It requires planning, adherence to best practices, and ongoing monitoring to ensure its effectiveness, but its implementation is an essential tool in your cybersecurity arsenal in an era where cyber threats continue to evolve.


If you’re interested in a career in network segmentation, get in touch with the team today.