Network segmentation is a cybersecurity tool that divides a network into different segments, each acting as its own network. Network segmentation allows a company’s experts to control traffic between segments based on a company’s policies.
Businesses use segmentation to improve their cybersecurity, improve monitoring, increase network performance, and find vulnerabilities.
See below to learn all about how a company successfully performs network segments:
- What is Network Segmentation?
- 7 Steps to Segment Your Network
- Identify the Most Valuable Assets and Data
- Classify Each Asset With a Label
- Detect and Create a Map of the Network and Data Flow
- Determine How a Company Wants to Segment Their Network
- Deploy a Network Traffic Segmentation Gateway
- Produce a Company-Wide Access Control Policy
- Perform Audits, Reviews, and Automate Network
- Bottom Line: Network Segmentation
What is Network Segmentation?
Network segmentation is an organizational tactic to divide a company’s network into segments or subnets. Each segment and subnet acts as its own network. This helps network administrators track the flow of traffic between the different segments based on the company’s needs.
Network segmentation is a tool that helps improve monitoring, increase performance, and enhance cybersecurity needs within a business. Network segmentation can prevent unauthorized users, allowing only the company to access valuable customer information.
To learn more, also see: What is Data Segmentation?
7 Steps to Segment Your Network
1. Identify the Most Valuable Assets and Data
Data and company assets are driving the value and growth of businesses.
A company should analyze its network to see which data and assets need the most protection. Valuable assets can include a customer database or employee information. To determine how to value data, there are three factors:
- Growth: Finding the growth in data over time can be beneficial in seeing patterns between current and future data.
- Return: If the asset has to do with customer data, trust and money are large parts to consider.
- Risk: The risk of losing data is a consideration, making it helpful to find the correct way to segment the valuable data.
2. Classify Each Asset With a Label
Labeling assets by high, medium, and low importance helps a company identify and prioritize where they should focus their network security efforts. To determine value, a company must consider sensitivity:
| Access Limitations | If Publicly Accessed | Types | |
|---|---|---|---|
| Low Sensitivity | Public access | Can be used or redistributed without any problems | Job descriptions and public website content |
| Medium Sensitivity | Company access | A loss can provide a substantial negative impact | Policies, emails, and documents |
| High Sensitivity | Confidential access | A loss is detrimental to a company | Financial records and trade secrets |
While not all data and assets fall under these sensitivities, it is a helpful way to begin labeling. These labels will define trust and protection within the network.
3. Detect and Create a Map of the Network and Data Flow
To detect and create a map of network and data flow, a company should check every step of the department’s network using labels to determine essential data and network flow.
While mapping the data and network, an expert should note how data flows, how the data is transferred, and the methods a company uses.
Industry experts recommend checking all data flows to map:
- Northbound traffic is the data flow leaving the company’s network.
- East-West traffic progresses between systems in the network’s perimeter.
- Southbound traffic is when data enters a company’s network segment.
Network segmentation assists in improving network security by breaking down the network into segments.
4. Determine How a Company Wants to Segment the Network
Once a map of the network and data flow is collected, a company must determine how to segment the network. While firewalls are usually a company’s pick, they are not the only form of network segmentation:
- Switches are the second-most used way to segment a network. Companies often use switches internally while using firewalls in segmenting network zones.
- Air gaps help segmentation achieve two network connections distributed through two internet providers.
- Analog phone lines are an offline way to segment a network. They can be implemented and configured to have no risk of network intrusion.
- Virtual local area networks (LANs) are broadcast domains that can provide partitioning and isolation within a network and implement the network design in deployment.
- Point-to-point encryption is another way of segmenting a network, but it can also eliminate any need for segmentation.
5. Deploy a Network Traffic Segmentation Gateway
Network segment boundaries must be completed quickly to apply controls on access within each network segment. Access controls are necessary for all network segments. To have a segment boundary, all network traffic that enters and exits a segment must go through the gateway.
“Deployed properly, both [network segment boundaries and access controls] provide a flexible way to perform network segmentation, and traffic can be dynamically directed to an application-aware firewall when traversing segments,” said the National Security Agency.
6. Produce a Company-Wide Access Control Policy
A company-wide access control policy is vital, due to the possibility that a cybercriminal or rogue employee has unrestricted access.
“Access control policies are high-level requirements that specify how access is managed and who may access information under what circumstances,” according to the National Institute of Standards and Technology (NIST).
Company-wide access control policies should be decided based on most-to-least privilege, using whatever application or device an employee should have that is required to do their job.
7. Perform Audits, Reviews, and Automate Network
After deploying a segmentation gateway and creating company access control policies, the segmentation gateway can be built. Defining a network segmentation policy does require change as the company’s network changes.
Performing audits, reviews, and monitoring the network is needed for changes, but it will also help a company see if any risks or errors have come up.
Network segmentation tests can be cybersecurity audits, penetration tests, vulnerability scans, and risk assessments.
For more information, also see: Why Firewalls are Important for Network Security
Protect Your Company With Network Segmentation
The ability to isolate network segments can help prevent a small or large breach. A company’s network must handle large volumes of traffic as a company grows or changes.
Network segmentation offers accessibility, better performance, and helps protect the company as a whole.
On a related topic: 5 Network Segmentation Case Studies
