What is Network Segmentation?
Network segmentation is a process of dividing a network into multiple zones and applying specific security protocols to each zone. The primary goal of network segmentation is to have increased control over the management of security and compliance. Network segmentation, also known as network partitioning or network isolation, makes it difficult for unauthorized users to compromise the network by preventing any single point of failure. There are numerous benefits of network segmentation:
- Robust security. Network segmentation minimizes risks to security by creating a multi-layer attack surface that prevents lateral network attacks (cyberattack techniques where a threat actor gains initial access to a network and then moves deeper into the network in search of sensitive data and other high-value assets). If a cyberattacker breaches your first perimeter of defense in a segmented network, they will be contained within the network segment that they access.
- Performance. With traffic being limited to certain zones based on need, the number of hosts and users within a subnet will be reduced. This decreases congestion and enhances operational performance across the board.
- Compliance. Network segmentation allows you to separate regulated data from other systems so that it is easier to apply targeted policies to manage compliance.
- Network monitoring. When a network is divided into segments, it is easier to identify threats and isolate incidents, preventing and/or limiting damage.
Examples of network segments include:
- Virtual Local Area Networks (VLANs). Networks are typically segmented with VLANs or subnets. VLANs create smaller network segments that virtually connect hosts, while subnets use IP addresses connected by networking devices.
- Firewall segmentation. Firewalls are deployed inside the network to create internal zones that partition functional areas from each other.
- Software Defined Networking (SDN). SDN segmenting is an approach to networking that uses software-based controllers or application programming interfaces (APIs) to communicate with underlying hardware infrastructure and direct traffic on a network.
Best practices for network segmentation include:
- Least privilege. Minimize who and what has access within and across systems according to need. Limit hosts, services, users, and networks from accessing data, resources, and functions that are beyond the scope of their responsibilities.
- Limit third parties. Third-party remote access weakens the security of your network as you are placing trust in the security and privacy practices of these third parties, which may be significantly inferior to your own. For third parties that need access to your network, create isolated portals for their use so that they do not have broader access to your sensitive and confidential information.
- Do not over-segment. Creating too many zones adds unnecessary complexity and makes your network more difficult to manage.
- Consolidate similar resources. Combine similar network resources into distinct databases to streamline security policies and protect data.