How do you reduce the attack surface with network segmentation?

1 What is network segmentation?

Network segmentation is the process of splitting a network into logical or physical segments that have different access policies and security controls. Each segment can have its own firewall, router, switch, VLAN, subnet, or VPN to isolate it from the rest of the network. Network segmentation can be applied at different layers of the network architecture, such as the core, distribution, or access layer, depending on the network design and security objectives.

2 Why is network segmentation important?

Network segmentation is an essential security measure as it can provide many benefits, such as reducing the attack surface and containing the impact of an attack. By limiting exposure of sensitive data and devices to only authorized users and segments, you can reduce the chances of an attacker finding and exploiting a vulnerability in your network. Additionally, isolating segments from each other can prevent an attacker from spreading malware to other segments. Furthermore, separating segments based on their functions and roles enables you to identify and track the normal and abnormal traffic patterns and behaviors of each segment. This makes it easier to detect and respond to a potential data breach in a timely manner.

3 How to implement network segmentation effectively?

Network segmentation is not a one-size-fits-all solution and requires careful planning, analysis, and testing to ensure it meets your network security needs and goals. To implement network segmentation effectively, you should define your network security objectives and requirements, map out your network topology and inventory, identify and classify your network segments, configure and enforce policies and controls for each segment, and test and validate the configuration and functionality. When defining objectives and requirements, consider the threats and risks you want to mitigate as well as compliance and regulatory standards. For mapping out the topology, consider devices, systems, data, connections, configurations, communications, functions, etc. Identifying and classifying your segments includes using criteria like IP addresses, MAC addresses, ports, protocols, or users. Configuring policies and controls includes using firewalls, routers, switches, VLANs, subnets or VPNs. Lastly, testing the configuration involves verifying that the segments are working as intended while measuring the impact of network segmentation on security, performance, and availability.

4 What are some network segmentation best practices?

Network segmentation is a process that requires ongoing maintenance and improvement to stay effective and efficient. To ensure that your network segmentation strategy remains up-to-date, you should review and update your network segments regularly. Additionally, you should apply the principle of least privilege, which grants users or devices the minimum level of access and permissions needed to perform their tasks. Finally, you should implement zero trust network security, which requires continuous verification and validation of every user and device before granting them access to a network segment or resource. This can help you enhance visibility and monitoring of network activity, as well as prevent unauthorized or malicious access.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?