Hackers are always looking for new ways to enter secure networks. Once inside, they can steal confidential information, conduct ransomware attacks, and more. Network security is therefore an important concern for any business.

One way to protect a system from attack is to use network segmentation. It doesn't necessarily keep hackers out of a network, but it can significantly reduce the damage that they are capable of doing if they find a way in.

So what is network segmentation and how should it be implemented?

What Is Network Segmentation?

Network segmentation is the act of dividing up a network into smaller segments. All of these segments act as smaller, independent networks. Users are then provided access to individual segments rather than the network as a whole.

Network segmentation has many advantages but from a security standpoint, its primary purpose is to restrict access to important systems. If a hacker breaches one part of a network, they shouldn't automatically have access to all of it. Network segmentation can also protect against insider threats.

How Does Network Segmentation Work?

Network segmentation can be carried out either physically or logically.

Physical segmentation involves a network being divided up into different subnets. The subnets are then separated using either physical or virtual firewalls.

Logical segmentation also involves a network being divided up into subnets but access is controlled using VLANs or network addressing schemes.

Physical segmentation is easier to implement. But it is usually more expensive because it often requires new wiring and equipment. Logical segmentation is more flexible and it allows adjustments to be made without changing any hardware.

Security Advantages of Network Segmentation

If implemented correctly, network segmentation offers a range of security advantages.

Increased Data Privacy

Network segmentation allows you to keep your most private data on its own network and to limit what other networks have access to it. If a network intrusion occurs, this may prevent the hacker from gaining access to confidential information.

Slow Down Hackers

Network segmentation can significantly reduce the damage caused by a network intrusion. In a properly segmented network, any intruder will only have access to a single segment. They may attempt to access other segments, but as they are doing so, your business has time to react. Ideally, intruders are only given access to unimportant systems before they are discovered and repelled.

Implement Least Privilege

Network segmentation is an important part of implementing policies of least privilege. Least privilege policies are based on the idea that all users are only provided the level of access or privilege required to do their work.

It makes malicious activity by insider threats harder to perform and reduces the threat posed by stolen credentials. Network segmentation is useful for this purpose because it allows users to be verified as they travel around a network.

Increased Monitoring

Network segmentation makes it easier to monitor a network and track users as they access different areas. This is useful for preventing malicious actors from going where they are not supposed to. It may also help to identify suspicious behavior by legitimate users. This can be achieved by logging all users as they access different segments.

Faster Incident Response

In order to repel a network intruder, the IT team needs to know where the intrusion is occurring. Network segmentation can provide this information by narrowing down the location to a single segment and keeping them there. This can significantly increase the speed of incident response.

Increase IoT Security

IoT devices are an increasingly common part of business networks. While these devices are useful, they are also popular targets for hackers due to their inherently poor security. Network segmentation allows these devices to be kept on their own network. If such a device is breached, the hacker won't be able to use it to access the rest of the network.

How to Implement Network Segmentation

The ability of network segmentation to increase security depends on how it is implemented.

Keep Private Data Separate

Prior to implementing network segmentation, all business assets should be classified according to risk. The assets with the most valuable data, such as customer information, should be kept separate from everything else. Access to that segment should then be tightly controlled.

Implement Least Privilege

Each user of the network should only have access to the specific segment required to perform their job. Particular attention should be paid to who has access to any segments which have been classified as being high risk.

Group Similar Assets

Assets that are similar in terms of risk and that are often accessed by the same users should be put into the same segment, where possible. This reduces the complexity of the network and makes it easier for users to access what they need. It also allows security policies for similar assets to be updated in bulk.

It can be tempting to add as many segments as possible because this obviously makes it more difficult for hackers to access anything. Over-segmentation, however, also makes things more difficult for legitimate users.

Consider Legitimate and Illegitimate Users

Network architecture should be designed by considering both legitimate and illegitimate users. You don't want to keep authenticating legitimate users but every barrier that has to be crossed by a hacker is useful. When deciding how segments are connected, try to incorporate both scenarios.

Restrict Third Party Access

Third party access is a requirement of many business networks, but it also carries significant risk. If the third party is breached, your network can also be compromised. Network segmentation should take this into account and be designed so that third parties are unable to access any private information whatsoever.

Segmentation Is an Important Part of Network Security

Network segmentation is a powerful tool for preventing a network intruder from accessing confidential information or otherwise attacking a business. It also allows users of a network to be monitored and this reduces the threat posed by insider threats.

The effectiveness of network segmentation depends on implementation. Segmentation needs to be performed so that confidential information is difficult to access but not at the cost of legitimate users being unable to access required information.