Key Points:

• Network Segmentation involves dividing a network into smaller segments for security and reduces the attack surface for hackers to penetrate.
• It helps enhance data security, aids compliance, and improves performance.
• Implementing Network Segmentation involves assessing your network, setting goals, choosing technology, creating segments, adding security, testing, educating employees, and regular reviews.
• Metomic's data security tool adds another layer of security to your business, by minimising the amount of sensitive data you hold in your SaaS apps like Slack, Google Drive, and Microsoft Teams.

As the cost of a data breach continues to skyrocket, averaging $4.45M in 2023 , you might be looking for ways to secure your most sensitive data.

Network segmentation offers an extra layer of security for your business, that can isolate a data breach, and help you spot any anomalies from insider threats.

What is the definition of network segmentation?

Network segmentation involves dividing a computer network into smaller parts in order to improve security and reduce your attack surface.

Rather than one overall network working off its own rules, the smaller segments operate completely independently, with their own access controls and security policies in place. They could be divided based on the departments they cater for, or the sensitivity of data being transmitted.

For example, businesses who operate a guest Wi-Fi network for their visitors have network segmentation in place. The guest network will work entirely separate from the internal network, limiting access for visitors and isolating the company’s internal resources.

This can prevent unauthorised access to sensitive data on the company network.

Why is network segmentation important?

1. Puts the security team in control

Implementing network segmentation allows you to take a proactive approach against data breaches, putting you in control of your data security posture and minimising the risk of financial and reputational losses that could occur as a result.

2. Reduce Attack Surface

Isolating networks also means that if you were to suffer a data breach, you could quickly react to the incident, knowing that your other networks wouldn’t be affected. With your attack surface reduced, the risk of sensitive data being exposed is minimised, as only authorised users will be able to access it.

3. Compliance

If your business needs to comply with regulations such as PCI DSS, you might also be required to have network segmentation, or other security measures in place. By restricting access to sensitive data, you can ensure that you’re doing everything you can to keep sensitive data safe. For instance, if credit card information is isolated, a data breach in one network won’t necessarily reach your customers’ financial data.

As well as the benefit to your overall security, network segmentation can improve performance by reducing unnecessary traffic across your network.

Who needs network segmentation?

Network segmentation is crucial for many organisations, especially those dealing with sensitive data or complex IT environments.

Take healthcare providers, for example. They need to protect patient information and comply with regulations like HIPAA, and network segmentation helps keep medical records secure and critical systems isolated.

Retailers, on the other hand, often aim for PCI DSS compliance. By segmenting their networks, they can ensure cardholder data stays separate and secure.

Large enterprises with sprawling IT infrastructures also see great benefits from network segmentation. It helps manage traffic and boosts security across various departments, reducing the risk of a single breach spreading throughout the entire network.

Educational institutions, with their diverse mix of users and devices, can use segmentation to protect administrative data while still providing secure access for students and faculty.

In short, if your organisation is looking to enhance security, comply with regulatory standards, or improve network performance, network segmentation is definitely worth considering.

The 4 types of network segmentation

You can segment networks by a range of different methods, depending on what your needs are as a business:

1. Physical Segmentation

If you have critical systems that need to be isolated, physical segmentation could help you protect them. You can use different devices, such as routers, to do this.

2. Virtual Segmentation (or Logical Segmentation)

Rather than physically separating networks, logical segmentation relies on access controls and network policies instead. Using VLANs (Virtual Local Area Networks) to achieve this, logical segmentation can be easier to manage than physical.

3. Perimeter Based Segmentation

This focuses on the perimeter of the company network, separating the internal from the external. Traditionally, anything external was not trusted while anything internal was, but this is no longer the case. Even if you implement perimeter-based segmentation, you should also focus on your access controls internally to ensure sensitive data is protected as much as possible.

4. Role-Based Segmentation

Grouping users based on their roles within the organisation, you can approve or deny access to various network resources that are necessary/unnecessary for their job function. If someone from the Marketing department tried to access sensitive HR data, for instance, this could be denied and flagged.

5. Application Segmentation

With many different apps to manage, you may opt to place them in their own segments, to prevent any interference between apps, and secure any sensitive data held within.

11 Best practises for implementing network segmentation for better security

Implementing network segmentation is a strategic move to enhance your security posture and streamline network management.

Here are some best practices to ensure effective and efficient network segmentation:

1. Assess your current network

Begin by thoroughly understanding your current network layout. Identify all connected devices, map out data flows, and pinpoint where sensitive data resides. Highlight potential security risks and note areas where segmentation could provide the most benefit.

2. Define clear goals

Determine what you aim to achieve with network segmentation. Are you looking to protect sensitive data, improve compliance, or enhance overall network performance? Clearly defined goals will guide your segmentation strategy and help prioritise resources.

3. Choose the right technology

Decide on the appropriate technology to segment your network. Options include VLANs (Virtual Local Area Networks), firewalls, and Software-Defined Networking (SDN) solutions. Each technology has its strengths and should be selected based on your specific needs and infrastructure.

4. Implement role-based access control (RBAC)

Utilise RBAC to group users based on their roles within the organisation. By defining access levels according to job functions, you can ensure that employees only have access to the data necessary for their roles, enhancing security and reducing the risk of data breaches.

5. Create logical segments

Design logical segments based on your assessment and goals. These segments could be departmental, by data sensitivity, or application-based. Logical segmentation allows for more flexible management compared to physical segmentation.

6. Enforce comprehensive security policies

Set up comprehensive security policies for each segment. Use firewalls, intrusion detection systems (IDS), and encryption to protect data within each segment. Ensure that these policies are consistently enforced across the network.

7. Monitor and audit regularly

Continuous monitoring and regular audits are crucial. Implement network monitoring tools to keep an eye on traffic patterns and detect any anomalies. Regular audits will help identify and rectify weaknesses in your segmentation strategy.

8. Educate your employees

Inform and train your employees about the new network segmentation setup. Ensure they understand how to access the information they need and the importance of following security protocols. Employee awareness is key to maintaining a secure network environment.

9. Avoid over-segmentation

While segmentation is beneficial, over-segmentation can lead to unnecessary complexity and management overhead. Aim for a balance where segments are sufficient to isolate critical data and systems but not so granular that they become cumbersome to manage.

10. Visualise your network

Use network diagrams to visualise your segmented network. This helps in understanding the relationships and dependencies between segments, making it easier to manage and troubleshoot the network.

11. Regularly review and update

Network requirements evolve over time. Regularly review your segmentation strategy to ensure it still aligns with your organisational goals and security needs. Update segments and policies as necessary to adapt to new threats and changes in the network environment.

What not to do with network segmentation

While network segmentation offers many benefits, there are common pitfalls to avoid.

These include:

• Neglecting regular updates: Don't treat segmentation as a "set it and forget it" solution. Regular reviews and updates are crucial to maintaining security and performance.
• Overcomplicating policies: Avoid overly complex segmentation policies that can be hard to manage and lead to misconfigurations. Simplicity and clarity are key.
• Insufficient training: Failing to properly train your IT staff and employees on new segmentation policies can lead to breaches or operational issues.
• Isolating segmentation from broader security: Network segmentation should complement other security measures, not replace them. Ensure integration with your overall data security strategy.
• Under-segmenting the network: Be wary of under-segmenting your network, which can leave you vulnerable to lateral movement by attackers. 

Proper planning and ongoing management are essential to avoid these risks and make the most of your segmentation efforts.

How can Metomic help?

Metomic's data security tool adds another layer of security to your business, by minimising the amount of sensitive data you hold in your SaaS apps like Slack, Google Drive, and Microsoft Teams.

We focus on detecting and protecting sensitive data, without getting in the way of your employees doing their jobs.

To see how it works, take a virtual tour of our platform and see where sensitive data is hiding.