9 Network Segmentation Best Practices – And Why They Matter for Cybersecurity

Almost every company in the world has suffered a network breach in the past. Businesses everywhere should strive to protect their data if they don’t want to face problems with threat actors and law enforcement alike – and network segmentation prevents that from happening. So, what are the network segmentation best practices?

Planning network segmentation ahead of time is a must, and so is implementing network monitoring right after. Avoiding over- and under-segmentation is key. Other measures, such as endpoint security management, are necessary to ensure full protection.

Does your company have network segmentation in place? Can you survive in a fast-paced, malware-infested tech world without it? Understanding how important network segmentation is, who can use it, and the best way to implement it is always necessary.

What’s Network Segmentation?

Network segmentation is a cybersecurity strategy that allows users to separate their network into different parts. In doing so, a user hedges their risks when it comes to possible cybersecurity attacks: a threat actor can’t compromise different segments from within.

Not deploying network segmentation means a threat actor may infiltrate your network – and they can freely roam inside your system once they achieve their goal.

In contrast, after implementing network segmentation, a threat actor may infiltrate a part of your system but will have zero chance to access other parts.

Why Is Network Segmentation Important?

Studies show one data breach is enough to bankrupt your business. That means you’re always one mistake away from closing shop – or worse: finding out you have to pay million-dollar fines because a malicious actor managed to break into your network and exposed your users.

However, not all breaches are equal. Having the right measures in place when an attack happens could greatly reduce the damage. For example, if a hacker manages to infect your network with ransomware, you could find yourself locked out of your system entirely – or only face that issue in a small portion of your network.

What’s the difference between those scenarios? The way you implement network segmentation, which prevents threats from spreading.

Who Needs To Learn About Network Segmentation?

Everyone needs to learn about network segmentation. Businesses, both big and small, must implement this method to prevent threat actors from freely accessing their systems or spreading malware.

At the same time, individual users should learn their way around network segmentation. We recommend dividing your personal network into three parts: admin network, guest network, and IoT network.

The admin network is for the owner alone, the guest network is for friends and family, and the IoT network is for smart appliances. Working that way helps prevent (or at least reduce the chance of) cyberattacks.

3 Types of Network Segmentation

  • Firewall Segmentation. This strategy requires having a firewall for each part of your network, meaning users will have to go through one every time they want to access a different side of their system. Unfortunately, firewall segmentation is rather inefficient because one misconfiguration mistake could potentially break the entire network.
  • SDN Segmentation. This strategy requires software to deploy network segmentation. For example, an API will control every aspect of this implementation. SDN segmentation comes with two issues: one, it has a single point of failure; two, most people find it difficult to implement.
  • VLAN Segmentation. This strategy separates your network using virtualization. It’s the go-to option for most users trying to implement segmentation. However, it doesn’t come without issues. VLAN has a few connectivity problems.

5 Dangers You Can Stop With Network Segmentation

1. Malware

Malware spreads fast. It takes one infected device to have a system-wide infection. Why can malware get everywhere so quickly? Because malware developers create their malicious software that way!

So, you know malware spreads everywhere it can by design. The question is, how can you stop that from happening? You can probably guess the answer is network segmentation.

Having your network divided into different segments is the same as having separate devices. In other words, malware can’t spread to different segments if you implement this strategy the right way.

2. Ransomware

Ransomware is a type of malware so dangerous that it deserves its own section. It’s a computer program that encrypts all the files it finds and asks for a ransom to bring the system back to normal. Most pieces of ransomware infect one device and quickly spread wherever possible.

However, you can stop the spread as soon as it starts – if you properly segment your network. Instead of having the ransomware lock you out of your network, you can lock out the ransomware from every device available. You can only do so if you implement this strategy before the infection takes place.

3. Privilege Escalation

Threat actors often infiltrate a network from the bottom. In other words, they access a system with the least privileges possible and look for exploits to escalate their position. They can get pretty far with enough technical knowledge and a bit of luck.

Network segmentation is a pretty straightforward way to prevent that from happening. Implementing this strategy adds an extra layer of protection, making it twice as hard for hackers to escalate their attacks.

4. Insider Threats

An insider threat is one of the biggest (and least talked about) problems a company could face. These threats are often former, compromised, or disgruntled employees who want to hurt a company from within. For example, a former IT employee who still has access to the entire network may leak confidential documents or sell them online.

Network segmentation can stop insider threats in many ways, though the biggest one is preventing anyone from accessing files they shouldn’t. So, if a disgruntled employee is trying to access sensitive data, they’ll probably get locked out in the process.

5. Noncompliance

Threat actors are not the only ones who can cause trouble. Law enforcement and government agencies can put your company in a tough spot too. Experts point out that not being compliant with regulatory laws often ends up in millions of dollars worth of fines, which could bankrupt your business the same way a data breach could.

So, how can network segmentation help with noncompliance? Implementing that segmentation strategy reduces the risk of a breach. It won’t stop it altogether (it’s impossible to do so) – but it will give you the tools to defend yourself from threat actors.

At the same time, having segmentation in place means you have people paying attention to your network, which increases the chance of finding out if something’s wrong before it does damage.

9 Network Segmentation Best Practices

1. Plan Your Network Ahead of Time

Network segmentation is like building a house. You can’t do so one room at a time, hoping it will look right by the time you finish. You need to roll up your sleeves, draw a blueprint, and then get to work.

What does that mean? It means you have to figure out how to divide your network before you do so! You need to evaluate which employees will get access to different parts too.

This strategy should feel like an overhaul – and you can’t overhaul a system one piece at a time. Doing so creates enough room for threat actors to hurt you.

2. Don’t Oversegment…

A big part of planning your network segmentation ahead is figuring out how many segments it’ll have. There’s no erring on the side of caution here: you have to create the right number of them.

In this scenario, going the extra mile and oversegmenting is the wrong way to go at it. Doing so will prevent workers from achieving their goals, increasing the chance of burnout.

Let’s go back to comparing network segmentation to building a house: imagine you get to live in a house where your kitchen is divided into four small spaces – and you have to open a door every time you want to take a pan to put over the stove; it’ll take forever to cook anything!

3. …And Don’t Undersegment

Under segmentation is the other side of the coin. You build fewer rooms in hopes of not going overboard. However, that also breeds trouble.

You’ll create a house with fewer rooms than necessary, thus defeating the purpose of network segmentation. In this scenario, you have a house with fewer walls and doors than needed – and criminals have an easier time accessing the different spaces once they break in.

Less is not more when it comes to network segmentation. Doing it right is the only way to go at it.

4. Categorize and Consolidate Resources

We have talked about how network segmentation is a system overhaul. As such, you need to take the time to view and review the many moving parts of your system. More often than not, that leads to you finding there are a few redundancies here and there. Take this opportunity to deal with them.

At the same time, putting similar resources under the same category will help efficiency and security. Grouping low-level resources together means there’s a smaller chance of suffering from an escalation attack.

In contrast, grouping low-level resources with high-risk material could lead to a data breach if a threat actor stumbles upon that seemingly-unimportant part of your network.

5. Employ Endpoint Management

Endpoints are the entry point to your network. We’re talking about phones and computers that connect to your system either in-house or remotely. Anything that connects to your network must be carefully assessed before allowing it in and monitored after it’s already connected.

The best way to take care of endpoints depends on how big your company is and how far you want to go when it comes to control. Many companies handle that kind of stuff for you if you feel like outsourcing that part of your security. There are also software solutions ready and waiting to take care of that for you.

6. Make It Easier for the Good Guys

Endpoint security is a big part of this process. However, that doesn’t mean you have to make it hard for employees to log in just because it feels more secure. Your network segmentation has two purposes: make it easier for the good guys to get in and impossible for the bad guys to do the same.

Let’s say you decide to implement a firewall between two sections of your network – but it never stops threat actors from doing harm: it only adds an extra roadblock for your employees instead. That means you have to reevaluate your segmentation strategy.

7. Vet Your Vendors (And Limit Their Access)

Companies are now paying closer attention to vendors and third parties: more than three-quarters of all companies are pursuing vendor consolidation, which means putting companies you do business with under scrutiny.

Why is vetting vendors important? Because it helps you figure out if you’re dealing with malicious actors disguised as vendors or compromised companies. Doing business with either one will hurt your organization.

For example, let’s say you’re doing business with a compromised vendor: after falling for a supply chain attack, a company could sell you malware-infected software, thus putting you in harm’s way without knowing. Limiting their access (thanks to network segmentation) could reduce the chance of a major attack happening.

8. Employ a Least-privilege Principle

A great way to prevent vendors from doing harm, insider threats from hurting your business, and negligence from taking place is to make the least-privilege principle a staple company-wide.

Doing so means employees will only get access to the files they need and can only take the actions they must. For example, someone in sales may need to read a report – but they can’t edit or delete it. The least-privilege principle allows a sales rep to read said report but nothing else, thus preventing that person from deleting it or otherwise.

It also limits access to parts of your network that a sales rep shouldn’t access (e.g., files from HR or resources from IT). This method should apply to every employee and department in your company.

9. Monitor Your Network

Last but not least, make sure you deploy other security strategies to prevent threat actors from accessing your data. Monitoring is always a big part of cybersecurity, and no amount of network segmentation will replace that.

Fortunately, segmentation makes it easier for your IT department to monitor your network. This strategy has plenty of benefits you’ll enjoy!


Network segmentation is a must for all organizations, no matter their size. It’s the easiest way to stop ransomware infections and other threats. Planning the segmentation ahead of time and monitoring your network right after is key. Protecting your network also means taking care of endpoints and vetting vendors. U.S. Cybersecurity has experts standing by to assist you with any network segmentation project.

Herman McCargo

Herman is a Microsoft Certified Security Engineer and Cybersecurity Specialist. He’s been in the technology field for over 20 years and has expertise working with the most critical technology infrastructures. He has a deep understanding of cyber risks, threat mitigation and prevention, and overseeing infrastructure.