A Comprehensive Guide on Micro-Segmentation

When you visit old European buildings and cathedrals, you’ll notice that many windows have small glass sections. If someone threw a rock at one of these windows, a small section would shatter, not the whole thing. In essence, micro-segmentation works on the same principle for cybersecurity.

Specifically, it allows each app in your system to separate into a dedicated section. This way, the app will only use the system resources it needs. As a result, even if a cyberattack targets this section, it’s easily replaceable and won’t affect the rest of the system.

In this guide, I’ll go over all matters related to micro-segmentation. You’ll learn what it is, how it works, its benefits, and much more. Without any further delay, let’s get started.

What Is Micro-Segmentation?

Micro-segmentation is a cybersecurity method where you limit specific apps and actions by the amount of bandwidth and system resources they can use. The method relies on the principle that you shouldn’t give any app or process more resources than it needs.

To clarify further, micro-segmentation (MS) relies on dividing all available system resources into limited virtual drives. In turn, these drives will strictly match the process you give them. This will limit the following resources for those processes:

• CPU usage
• RAM usage
• ROM/cloud disk space available
• Bandwidth
• Network access
• Data access

Let’s now take a look at how micro-segmentation works.

How Does Micro-Segmentation Work?

If you don’t implement micro-segmentation, each app will have access to your entire system. In essence, micro-segmentation works by giving each app access to a tiny part of your entire system. If this “tiny part” becomes the target of a cyberattack, it’ll be much more noticeable but a lot less detrimental to your whole system.

The most common example is a server-client connection (also called “north-south”). Since MS can restrict bandwidth utilization, the client can’t send or receive more data packets than what was restricted by the system. In this scenario, it’s not something that you can change. Why? Because the system has zero bandwidth remaining.

However, the LAN or internet connection isn’t the only thing you can segment. In lateral system communications (also called “east-west”), it’s possible to segment processing power and disk space. As a result, this makes any potential attack even more restricted.

In some types of micro-segmentation, it’s possible to command all the segments from the back end as if they’re on the same system. However, best practices usually involve letting the apps work automatically and only monitoring from the back end.

You can set separate system rulesets inside each virtual machine. You can even have a separate cybersecurity infrastructure inside each VM, such as a firewall or compliance software.

So far, I’ve covered a brief definition and how micro-segmentation works. What about its benefits? Let’s look at those now.

Benefits of Micro-Segmentation

The biggest benefit of MS is compartmentalization. Because you divided your system into smaller sections, many cyberattacks will have difficulties passing through. This is just one benefit.

Below is a table showing some more benefits of MS across several sectors, as well as some limitations:

Sector	Benefit	Limitation
Cybersecurity	Reduced attack surface Improve attack reporting	Each segment would need specific cybersecurity attention
System Stability	Attacks and issues don’t affect the main system Easy automatic backups	Failure of the main system or cloud server would bring all virtual machines down
Application Updates	Failed updates don’t affect the main system Zero-day attacks only affect the VM with the app	Limited disk space and CPU power might stop updated applications
Outbound Communication	Less risk when communicating Strict limits to what you can send or receive	You can’t send messages to those outside the restricted parameters
Bandwidth Optimization	No chance for packet sending lag Ideal bandwidth distribution	Low-priority apps might get less bandwidth than they need
Function Monitoring	Each function has multiple parameters You can monitor all compartments from the same place	You can’t protect attacked VMs; you can only delete them
Compliance	Each compartment can have specific compliance solutions No chance of contradictory compliance	Some compliance rules might severely increase resource use

Next up are the features of micro-segmentation!

Features of Micro-Segmentation

While different types of micro-segmentation focus on different aspects of the system, implementing MS always follows the same principles. This fact alone can inform you of the features you should look for in a good MS system.

Generally, you should look for the following features:

• Monitoring
• Labeling
• Automation
• Risk Mitigation

Thankfully, almost every virtualization engine today will allow for all of these features. Overall, if you have a third party building your MS security, you’ll need easy accessibility to all of them.

Let’s now look at each of the above features in more detail.

Monitoring

To start, clear visibility is important. Monitoring is a huge part of any system. The same applies to MS. Because of this, you need to have a straightforward map from the main system to all the VMs. This visibility will allow you to make improvements and changes easily.

You should make all monitoring access panels available solely from the back end. Even if remote access is necessary, always ensure you have several additional layers of protection and encryption.

Labeling

Next, we have labeling and nomenclature. Unlike system segmentation in the past, you can make those labels human-centric and not computer-centric with VMs. You can call them regular names such as “email app” and “printer” instead of relying on local-assigned IP addresses.

It’s a good idea to devise a labeling system before you start with the first label. Otherwise, you may end up with names such as “email 1” and “email sec”, which will only become more confusing as time goes on. You also have future people to consider.

Automation

Another feature you should look for is automation. Following the map mentioned earlier, the system should be able to fill out rules and act upon them, even if issues pop up. New virtual machines should automatically be able to receive certain privileges and restrictions.

This is also where good labeling will prove beneficial. If you can quickly determine where any segment falls within the system, it’ll be easy to create rules about how many privileges those segments can have.

Risk Mitigation

Finally, we have risk mitigation. Any communication between the VMs or the main system should only be where necessary. Specifically, you’ll want to use automation to frequently restrict internal communication as much as possible. Similar to a valve, a rule can be in place to allow flow in one direction but not the other.

I hope you’re enjoying the ride so far. Next, I’ll cover the types of micro-segmentation you might expect to find out there.

Types of Micro-Segmentation

The differences between types of micro-segmentation lie in what you’re segmenting in the first place. Different businesses and specialty systems would benefit the most from focusing on aspects where much of their operational and cybersecurity worries lie.

Here are the 7 types of MS. They each focus on a unique aspect and have different specialty benefits, all outlined below.

Micro-Segmentation Type	Focus	Specialty Benefit
Application Segmentation	Key operating applications	Vulnerability mitigation
Environmental Segmentation	Sectors of operation	Clear division of resources
Application Tier-Level Segmentation	Inter-dependent applications	Apps can communicate with adjacent apps
Process-Based Nano-Segmentation	Individual app processes	Severely reduces the number of possible attack vectors
User Segmentation	Individual users	Sensitive data proliferation prevention
Container Segmentation	Stored data	Improved data privacy
Kubernetes Segmentation	Service-to-service communication	Improved data communication monitoring

Regretfully, these come with some challenges as well. These challenges are most commonly associated with network communication. I’ll now briefly cover some of these challenges before moving on to best-known practices.

Network Segmentation Challenges

The biggest issue with network segmentation, which comes under environmental segmentation, is that it’s hard to predict how many resources any app might potentially use. 

Namely, you’ll need to prioritize the implementation of the most important apps. Then, you’ll have to go down the list—the least important apps can share the same resources. 

Sometimes, updates on the compartmentalized apps and processes will increase the resource requirements for regular operations. Depending on your current situation, you might need to allow this at some points.

Thankfully, with a good system map, it’s not too difficult to reassess the allocation of system resources. However, this task might be very tedious with some types, such as process-based nano-segmentation.

Now that you know what’s out there, we can dive into the current best practices.

Best Practices for Successful Micro-Segmentation

To implement MS, it can be as easy as going through a checklist. But you should also keep some best practices in mind. Even if you don’t need to apply them all, it’s good to know them! So let’s go through some of these best practices to successfully implement micro-segmentation.

Design Best Practices

Firstly, you must have a clear system map. This map should always lead from the system’s main server to the function’s end users.

Start with the main server and an adjacent backup. Then, work your way through sectors of operation which you can separate. Each of those might need to have further apps and processes compartmentalized.

Overall, this strict hierarchy, with many non-connecting branches, will make your system easier to operate and harder to attack.

Define Your Boundaries

With micro-segmentation, it’s important to define your boundaries. To clarify, only allow necessary connections and resource utilization, and block everything else.

This approach makes it easy to allocate more resources if an app needs them.

Use an Application-Centric Approach

You don’t need to consider fairness and equality when it comes to app resource distribution. The apps only require the resources they currently need. Giving them more resources won’t make them work better. On the contrary, it might leave them vulnerable to cyberattacks.

Don’t simply allocate resources based on your bandwidth or processing power. Instead, focus on how much your key operating apps need and work from there.

Define Levels of Access

It’s important to define levels of access for your apps in MS. Work through each one to learn what information they’ll need, how large the data is, and when they can access it.

You should only maintain the availability of internal communication in well-established parameters. In addition to that, block everything else. If the need for more access arises, you can add only that to the allowlist.

Prioritize Implementation

Always prioritize and start with the main operating apps and communication points. Once you’ve successfully implemented micro-segmentation for those, you can include other apps and processes in the system. In short, prioritization makes the implementation much easier.

Use a Crawl-Walk-Run Implementation Model

With implementation, starting small before moving on to bigger and more complex systems is best. Set aside a single virtual machine and create a stress test. Envision its position in the system, and once you’re sure it works, you can move on to another.

Cybersecurity generally doesn’t appoint any style or speed points, so taking things slow before you’re comfortable with the system’s stability is wise.

Label Assets for Security

Not all of the virtual machines in the system need to have dedicated security measures. But, if some frequently receive data from unreliable sources (all sources outside your system), it’s always best to have those protected.

Moreover, you should label these VMs aptly. Thankfully, this is easy because you don’t need to use complex labels. You can simply call the VM “SECURED” on the indexing page.

Author and Configure Policies

All systems have operating, access, and security policies. In this case, each virtual machine should have its specific policy that will govern how to access it, who can access it, and for what reason.

These strict rules will improve monitoring, as anything outside the policy will be flagged as an issue. This approach could produce more false positives than issues, but it’s better to be safe than sorry.

Simulate and Validate Applications

Since you already have a virtual machine in place, testing and simulating attacks is cheap and easy. Once you’ve decided you’ve completed a segment, apply a stress test to see if anyone can compromise its security from the outside.

Testing that by yourself will prevent threat actors from testing it for you once they find a way to attack.

Lastly, I’ll focus on how to implement micro-segmentation for any general system. Hopefully, that will help you get a start before you apply the best practices we just went through.

How to Implement Micro-Segmentation

Implementing micro-segmentation is identical to implementing any virtual machine system. Once you know your resources, such as your server’s processing power, RAM, and bandwidth, you can separate those into virtual machines.

First, you’ll need an operating system for the virtual machine. In many cases, people use Linux OS, but options such as Android are also available. Then, you can allocate specific hardware resources to that virtual machine.

The final tally for these resources should include the app’s requirements and the assisting structure’s requirements. This structure can include any additional security and the virtual machine OS itself.

Finally, go through the best practice steps with each machine you make and set them in a system. You’ll see more benefits and security from micro-segmentation as the structure grows.

And there you go! It’s been quite the journey, hasn’t it? As always, it’s time to have a quick and simple recap!

Final Words

In conclusion, micro-segmentation is a cybersecurity method, and you should view it as one of the tools you have in your cybersecurity arsenal. If implemented correctly, it can vastly reduce the damage of an attack and can prevent most of them.

Micro-segmentation works by creating virtual machines for each key operating app you have or which you have connected with the outside world. Therefore, if someone attacks one of these VMs, the rest of your system will remain safe and sound.

As mentioned earlier, MS has many benefits. The main benefit is risk mitigation. If you need a quick refresher, feel free to refer back to the list of benefits.

When it comes to implementation, you’ll need to start slowly and work from the most important apps you use downwards. Thankfully, you can apply the best practices mentioned above to help keep you on track.

Overall, MS is slightly more hardware and network-intensive than some other solutions. However, it has the benefit of being virtually impossible to circumvent from the outside if done correctly.

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

FAQ

What can micro-segmentation do that a firewall can’t do?

Although virtual firewalls now exist to cater to virtual machines, the approach between them and MS is different. While firewalls are “opt-out” and allow everything but known threats, micro-segmentation blocks everything except what you specifically allow.

Why is micro-segmentation zero-trust?

The current approach to cybersecurity is that everything is malware until proven otherwise, and you need to prove otherwise to access it. Similar to zero-trust network access, micro-segmentation needs specific conditions to communicate and is otherwise locked out.

Does micro-segmentation use more bandwidth?

No. While the internal connections might need more bandwidth, or even advanced bandwidth solutions, the external bandwidth used by the processes will be the same inside the micro-segments as on a unified system.

Is micro-segmentation a cybersecurity term?

It is, amongst others. Aside from cybersecurity, you can see the term commonly used in sales, business consulting, and marketing. The term can sometimes overlap between industries, such as with intent data, a data science term used with sales and marketing.

Does micro-segmentation stop cyberattacks?

Not necessarily. While each segment can have dedicated anti-malware and anti-spyware software, the system itself isn’t meant to stop any type of cybercrime. Instead, it hinders cyberattackers and makes the attacks much less effective.

Resources

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TechGenix: Article on Containerization

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TechGenix: Article on Cloud Data Management 

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