Network Segmentation Best Practices for Your Organization

Your network is your company’s greatest strength. However, it can also be your company’s greatest weakness if you don’t protect it well. Networks have changed a lot since the days of simple switches, routers, and a flat network structure. Today, we have on-prem servers, devices with cloud services, and a distributed workforce. With more complex networks, network segmentation has never been more critical than now. 

In this article, I’ll cover what network segmentation is, its benefits, and some examples. I’ll also compare it with micro-segmentation and share some best practices you can apply to your organization. Let’s begin.

What Is Network Segmentation?

Network segmentation involves the partition or encapsulation of your network into separate sections. By segmenting your network, you can prevent a single point of failure. Additionally, if a cyberattacker accessed your network, they’d only have access to one section instead of your whole network. Network segmentation can also give your cybersecurity time to remediate a breach before it escalates into something worse.

Network segmentation is the opposite of having a flat network. A flat network typically connects all your systems without intermediary devices, like bridges, switches, and routers. While flat networks do offer great speed between systems, they’re also vulnerable because they’re so open. In many cases, having a segmented network is the way to go.

Let’s go over some network segmentation benefits to give you a better idea of how good it is.

Benefits of Network Segmentation

Segmenting your network offers many benefits. In this section, I’ll discuss a few of those benefits in more detail.

Strong Data Protection 

The more you segment and control your network traffic, the more secure your data becomes. Essentially, network segmentation limits the number of network sections that can access your data. In turn, this leads to increased data security.

Effective Threat Containment 

A cyberattacker will be confined to a specific subnet if they breach your network. In turn, it’ll take them time to try and break into the rest of the system. Your security teams can assess the threat and increase security in the other subnets and network sections.

Limited Access Control 

By using the policy of least privilege, you can limit the number of people that have access to a particular area. Doing this decreases the chances that a cyberattacker will gain access to your network. This is because people are usually the weakest link in the system (think phishing emails, for instance).

Improved Monitoring 

As you segment your network, you’ll create more points where you can observe and monitor it. The more points you have in place, the easier it is to detect suspicious events.

Fast Response Rates

This benefit correlates with improved monitoring, allowing your security team quick reaction times. Segmentation will narrow the focus of the issue and, in turn, create a quicker response.

Easy Damage Control

A cyberattacker who breaks into a segmented network can’t inflict too much damage. This is because they have limited access to the system. Since the attacker only has access to a small part of the system, any damage they inflict is easily repairable.

So, now that you know what network segmentation is and its benefits, let’s look at a few examples of how you can segment your network.

3 Network Segmentation Examples

Below are 3 examples of how you can segment your network. 

1. Virtual Local Area Networks (VLANs) Segmentation

Generally, you segment networks with VLANs or subnets. VLANs make smaller sections of the network that virtually connect to the host. On the other hand, subnets use IP addresses to segment a network. While these are traditional network segmentation methods, they require constant maintenance and re-architecting. 

2. Firewall Segmentation

You can also use a firewall to partition a network, but differently from VLANs and subnets. You can deploy a firewall within your network to create internal regions that separate systems and function systems from each other.

3. Software-Defined Networking (SDN) Segmentation

SDN segmentation is a newer approach to network segmentation known as SDN-automated overlay. While this method is newer and uses software for the segmentation, it can be challenging to handle the associated micro-segmentation. 

Speaking of micro-segmentation, let’s look at how it compares with network segmentation.

Network Segmentation vs Micro-Segmentation

Micro-segmentation originated as a way to moderate lateral traffic between servers in the same segment. However, it has evolved to include intra-segment traffic. 

For example, this means that server A can talk to server B or Application A can communicate with Host B, and so on. To clarify, this only works if the identity of the requesting resources matches the permission configured for that server/application/host/user.

Below is a simple table highlighting the differences between network segmentation and micro-segmentation. 

When you think about network segmentation and micro-segmentation, it’s not about using one over the other. Instead, you should consider using both to ensure your network’s optimal protection. This combination is one of the best practices out there. 

Speaking of best practices, let’s look at those now!

5 Network Segmentation Best Practices

Here are the top 5 network segmentation best practices. This isn’t an exhaustive list of everything you can implement, but these are some of the best recommendations. Let’s dive in.

1. Monitor and Audit Your Networks Continuously

As mentioned earlier, monitoring and observability are extremely important. If you segment your network, these tasks become easier. In turn, your response time to attacks will improve as well.

2. Follow the Principle of Least Privilege

Based on the principle of least privilege, you should know who’s accessing your network. Moreover, you should understand how to restrict permissions based on the principle of least privilege. Overall, this reduces the chances of a cyberattacker breaching your network. Remember that people are the biggest vulnerability in a network.

3. Use Whitelists

Whitelisting IP addresses is a great way to protect your network and allow remote workers to connect to it. A whitelist works best in conjunction with a VPN due to the static nature of a VPN IP. This contrasts with IPs that offer dynamic IPs. In essence, a whitelist will only allow access from the IPs you put into it.

4. Make It Easier for Third-Parties to Access Your Network

You’ll want to ensure that third parties have the easy access they need to your systems, and bad actors don’t. Sometimes, depending on the architecture, it might be harder for your third-party vendors to access your network than it should be. You’ll need to reorganize and re-architect that if this is the case. 

5. Map Data Flows Across Your Network

As previously mentioned, network segmentation makes it harder for a cyberattacker to access your network by breaking it into isolated segments. Despite this, you’ll want to restrict network traffic accordingly. 

Northbound traffic leaves the network. For example, this can be an employee visiting a website from a managed device connected to the corporate network.

East-west traffic moves between systems inside the segmented network sections. An example of this would be a front-end server and a database in the data center network.

Southbound traffic includes data entering a network segment or zone. For instance, this could be a customer or employee accessing an on-prem web server located in a segmented network or the company’s intranet.

Flows of data and traffic aside, we’ve covered a lot in this article, so it’s time for a recap.

Final Words

To conclude, network segmentation is vital to the success and security of any network. Without it, you’re vulnerable to cyberattacks and other related issues. When you segment your network, it becomes much easier to manage and monitor. Furthermore, if a cyberattacker does manage to breach it, they’ll only have access to one part of it. In turn, this allows you to easily remediate the issue in preparation for future attacks.

Network segmentation can take a variety of forms. I covered 3 examples of network segmentation: VLAN segmentation, firewall segmentation, and SDN segmentation. Consider your requirements when choosing the right form for your business.

Lastly, remember to follow the network segmentation best practices I outlined. This includes following the principle of least privilege, using whitelists to manage access, and mapping data flows in your network, to name a few. 

Do you have more questions about network segmentation? Check out the FAQ and Resources sections below!

FAQ

What is network segmentation?

Network Segmentation involves taking your network and breaking it down into smaller sections. You can do this via VLANs or subnets in the classical sense of segmentation. Segmentation also allows you to easily manage your network and increase your overall network security.

What is the principle of least privilege?

The principle of least privilege states that a user should only have the necessary access rights to complete their task. Think of it as “need-to-know” information. If you need to know it, it’s important for your job. Likewise, if you don’t need to know it, it won’t affect your performance since it doesn’t help you do your job. This is also the case with access rights.

What is a firewall?

A firewall is a part of a network designed to block incoming or outgoing connections that don’t have the proper access rights. It does this to prevent unwanted access to your network. Furthermore, it can monitor traffic in your network.

What is a whitelist?

A whitelist is a list that allows users with listed IP addresses to have access to the network. You can’t access the network if you’re not on the list.

How does network segmentation differ from micro-segmentation?

Network segmentation breaks your network into smaller sections. On the other hand, micro-segmentation takes your applications and creates a virtual machine for each of them. In essence, micro-segmentation is much more granular than network segmentation.

Resources 

TechGenix: Article on Micro-Segmentation 

Learn about micro-segmentation in more detail.

TechGenix: Article on Network Infrastructure Security 

Explore what network infrastructure security is and why you need it. 

TechGenix: Article on Demilitarized Zones

Discover what a DMZ is and how you can use one to protect your network.

TechGenix: Article on Firewall-as-a-Service 

Find out everything you need to know about Firewalls-as-a-Service.

TechGenix: Guide on User and Entity Behavior Analytics

Read more about UEBA and how you can use it to detect cyberattackers.