Hackers are always looking for new ways to gain access to secure networks. Once inside, they can steal confidential information, carry out ransomware attacks, and more. Network security is therefore an important concern for any business.
One way to protect a system against attacks is to use network segmentation. This doesn’t necessarily prevent hackers from gaining access to a network, but it can greatly reduce the damage they are able to do if they find a way to break into it.
So what is network segmentation and how should it be implemented?
What is Network Segmentation?
Network segmentation is the process of dividing a network into smaller segments. All of these segments act as smaller, independent networks. Users then have access to individual segments rather than the network as a whole.
Network segmentation has many advantages, but from a security perspective, its primary purpose is to restrict access to important systems. If a hacker hacks part of a network, they shouldn’t automatically have access to everything. Network segmentation can also protect against insider threats.
How does network segmentation work?
Network segmentation can be done physically or logically.
Physical segmentation consists of dividing a network into different subnets. The subnets are then separated using physical or virtual firewalls.
Logical segmentation also involves a network being divided 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 allows adjustments to be made without changing hardware.
Benefits of Network Segmentation Security
If implemented correctly, network segmentation provides a range of security benefits.
Increased data privacy
Network segmentation allows you to keep your most private data on its own network and limit other networks that have access to it. If a network intrusion occurs, it may prevent the hacker from accessing confidential information.
Slow down pirates
Network segmentation can significantly reduce the damage caused by a network intrusion. In a properly segmented network, any intruder will only have access to one segment. They may try to access other segments, but doing so gives your business time to react. Ideally, intruders only gain access to unimportant systems before being discovered and repelled.
Implement least privilege
Network segmentation is an important part of implementing least privilege policies. Least privilege policies are based on the idea that all users are given only the level of access or privilege required to do their job.
This makes malicious activities of insider threats more difficult 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 move across a network.
Network segmentation makes it easier to monitor a network and track users as they access different areas. This is useful to prevent malicious actors from going where they are not supposed to. It can also help identify suspicious behavior by legitimate users. This can be achieved by registering all users when they access different segments.
Faster incident response
In order to fend off an intruder on the network, the IT team must know where the intrusion is occurring. Network segmentation can provide this information by limiting the location to a single segment and keeping it there. This can significantly increase incident response speed.
Increase IoT security
IoT devices are an increasingly common part of enterprise networks. While these devices are useful, they are also popular targets for hackers due to their low inherent security. Network segmentation keeps these devices on their own network. If such a device is hacked, the hacker will not 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
Before implementing network segmentation, all business assets must be classified according to risk. Assets containing the most valuable data, such as customer information, should be kept separate from everything else. Access to this segment must then be tightly controlled.
Implement least privilege
Each network user should only have access to the specific segment required to perform their job. Careful consideration should be given to who has access to all segments that have been classified as high risk.
Group similar assets
Assets that are similar in risk and often accessed by the same users should be placed in the same segment, whenever possible. This reduces network complexity and makes it easier for users to access what they need. It also allows bulk updating of security policies of similar assets.
It can be tempting to add as many segments as possible, as that obviously makes it harder for hackers to access anything. However, over-segmentation also makes things harder for legitimate users.
Consider legitimate and illegitimate users
Network architecture should be designed with both legitimate and illegitimate users in mind. You don’t want to keep authenticating legitimate users, but every barrier that a hacker has to overcome is helpful. When deciding how the segments are connected, try to incorporate both scenarios.
Restrict Third Party Access
Third-party access is a requirement of many corporate networks, but it also carries significant risks. If the third party is hacked, your network may also be compromised. Network segmentation must take this into account and be designed in such a way that third parties cannot access any private information whatsoever.
Segmentation is an important part of network security
Network segmentation is a powerful tool to prevent a network intruder from accessing confidential information or otherwise attacking a business. It also helps to monitor users on a network, reducing the threat posed by insider threats.
The effectiveness of network segmentation is implementation dependent. Segmentation should be done so that confidential information is difficult to access, but not at the expense of legitimate users who cannot access the required information.