What is Microsegmentation?

Perimeter or network security and microsegmentation are two different security strategies that address separate aspects of network security. Perimeter security provides a first line of defense against external threats by protecting the outer perimeter of a network—typically at the network edge—by limiting access to the network from outside sources. It inspects “north-south” (client to server) traffic that attempts to cross the security perimeter and stops malicious traffic. Perimeter security is usually achieved through technologies such as firewalls, intrusion detection and prevention systems, and VPNs.

Microsegmentation focuses on the internal security of a network by dividing it into smaller segments or zones and applying granular security controls to each segment. This allows organizations to control “east-west” lateral traffic within the network and at the application or workload level to reduce the potential attack surface.

Microsegmentation can present challenges for network performance and security if it is not properly planned and implemented.

• Performance degradation. Microsegmentation can make the network more complex to monitor and manage, and segmenting the network too finely or applying too many security policies can impact network traffic patterns and limit network performance. Applying security policies to each segment creates additional overhead on the network, which can lead to latency and slower network performance.
• Security gaps. While microsegmentation is a powerful security technique, policies need to be configured correctly to ensure that all traffic is properly filtered and allowed/denied. Misconfigurations and inconsistent policy enforcement can lead to security gaps, blocked legitimate traffic, and potential vulnerabilities.

Organizations should carefully plan their microsegmentation strategy, including the number and size of segments, the security policies to be applied, and the impact on network traffic patterns. Proper testing and monitoring should be conducted to ensure that microsegmentation does not negatively impact network performance or introduce security gaps.

Microsegmentation enables organizations to create secure zones or segments within their networks, providing granular control over network traffic and minimizing the attack surface. Each segment is then secured using policies and controls that allow only authorized traffic to flow between segments.

Microsegmentation is typically implemented using software-defined networking (SDN), which enables the creation of virtual networks that are independent of physical network infrastructure. Each of the network segments is secured using policies that define the types of traffic that are allowed to flow in and out of the segment. For example, access control lists (ACLs) can be used to control which users or devices are allowed to access each segment. Intrusion detection and prevention systems (IDPS) can be used to detect and block malicious activity within each segment. Encryption can be used to protect data as it moves between segments.

Microsegmentation provides granular visibility and control over network traffic, making it easier to identify unauthorized traffic and potential security breaches and respond quickly to security incidents.

There are three primary types of microsegmentation controls.

Agent-based microsegmentation controls use software agents installed on endpoints, such as servers, workstations, or other network devices, to enforce network segmentation policies. The agent continuously monitors and enforces the policies specific to that endpoint, and can be managed centrally through a management console, simplifying configuration and deployment policies across an organization's network.

Network-based microsegmentation controls use SDN to create virtual network segments, each with its own set of security policies and controls. These virtual segments are isolated from each other, which limits the potential for lateral movement by attackers. Policies and controls are enforced at the network layer, rather than at the endpoint level. This makes it possible to segment network traffic based on a wide range of factors, including user identity, application type, and network location.

Native cloud microsegmentation controls are specifically designed for cloud environments. They use cloud-native security features, such as network security groups and virtual private clouds to create virtual network segments and enforce security policies. These controls leverage the native security features of the cloud platform to provide granular security policies that are automatically enforced across all cloud instances.

Organizations may choose to implement one or more types of microsegmentation depending on their specific needs and goals. Common types of microsegmentation include the following.

Application Segmentation

Application segmentation protects individual applications by creating security policies that control access to specific application resources, such as databases, APIs, and web servers, helping to prevent unauthorized access and data breaches. It also allows organizations to enforce least privilege access controls, ensuring that users and applications have access only to the resources they need to perform their specific functions.

Tier Segmentation

Tier segmentation secures different tiers or layers of an application stack, such as the web tier, application tier, and database tier to prevent attackers from moving laterally within the application stack and accessing sensitive data or resources.

Environmental Segmentation

Securing different environments or zones within a network, such as development, testing, and production environments, allows organizations to enforce strict access controls to these environments and ensure that sensitive data and resources are only accessible to authorized users and applications.

Container Segmentation

Container segmentation secures individual containers or groups of containers within a containerized environment, reducing the attack surface and helping prevent attackers from moving laterally within the container environment. Without proper segmentation containers can potentially access each other's data and configuration files, which can result in security vulnerabilities.

Container Segmentation Best Practices

• Container isolation. Use technologies like Docker or Kubernetes to ensure that containers are isolated from the host system and from other containers on the same system. This prevents containers from accessing resources outside their designated scope.
• Network segmentation. Use network segmentation to limit the communication between containers and other network resources. This involves creating separate networks for each container and configuring firewall rules to allow or deny traffic between containers and ensure that only authorized communication is allowed.
• Role-based access control. Implement role-based access control (RBAC) to ensure that only authorized users can access and modify containers and related resources. RBAC frameworks like Kubernetes RBAC can be implemented to define and enforce user roles and permissions.
• Image signing. Use image signing to ensure that only trusted images are used to create containers. Digital signatures can help prevent container images from being tampered with or altered.
• Runtime protection. Use runtime protection to detect and respond to security threats during container runtime. Tools like runtime security agents and vulnerability scanners can monitor containers for signs of compromise and take appropriate action to mitigate risks.

User Segmentation in Cloud Security

• RBAC assigns users to specific roles or groups based on their responsibilities and access needs. Each role is associated with a set of permissions and access controls that are appropriate for that role. RBAC ensures that users can only access the resources and data that they need to do their jobs.
• Multi-factor authentication (MFA) requires users to provide two or more forms of authentication before they are granted access to a system or application. This can include a password, a security token, one-time access code, or biometric data. MFA is an effective way to prevent unauthorized access to cloud resources, particularly when combined with RBAC.
• Continuous monitoring involves regularly analyzing user activity and system logs for suspicious behavior or potential security threats. It can help identify anomalous behavior by alerting security teams to activity that falls outside of a user's normal access patterns or behaviors.
• Separation of duties ensures that no single user has complete control over a critical process or system. Segmenting users into different roles and responsibilities reduces the risk of fraud or errors and ensures that sensitive operations are performed by multiple employees.
• Regular access review involves routinely evaluating user access to systems and applications to ensure that users only have access to the resources they need. Access reviews can help to identify and remove unnecessary access rights, reducing the risk of unauthorized access.

Microsegmentation offers numerous benefits to organizations, including:

• Reduced attack surface: By breaking down the network into smaller segments, microsegmentation reduces the attack surface and makes it more difficult for attackers to gain access to critical assets.
• Improved breach containment: In the event of a breach, microsegmentation can help contain the impact of the attack by limiting the attacker's ability to move throughout the network. By isolating affected areas of the network, microsegmentation can prevent the spread of malware or other malicious activity, reducing the potential damage caused by the breach.
• Stronger regulatory compliance: Many regulatory frameworks require organizations to implement strong access controls and security measures to protect sensitive data. By ensuring that only authorized users and applications can access sensitive resources, microsegmentation can help organizations demonstrate compliance with regulatory standards.
• Simplified policy management: Microsegmentation can simplify policy management by allowing security policies to be applied to specific segments of the network. This can be particularly useful in large or complex networks, where managing policies for each individual device or user can be challenging.

Q: How is network segmentation different from microsegmentation?

A: Network segmentation and microsegmentation both improve network security and performance, but they are fundamentally different. Traditional network segmentation (sometimes called macro-segmentation) involves dividing a network into larger segments based on function or location. It typically focuses on traffic traveling “north-south” (client to server) in and out of the network.

Microsegmentation divides a network into smaller segments and applies unique security policies to them, providing a more granular level of control over east-west network access, with the ability to enforce zero-trust access controls. Microsegmentation applies security policies at the individual workload or application level, rather than at the network level.

Q: What is an application dependency?

A: Application dependency refers to the relationships and interactions between different applications and services within a networked environment. Understanding application dependencies is important for effective microsegmentation strategies, as access changes to one application or service can impact the performance or security of other applications and services. Application dependencies should be mapped before implementing microsegmentation.

Q: What are firewall policies?

A: Firewall policies are rules that define how an organization’s firewalls allow or deny traffic between different segments of a network or between a network and the Internet. Firewall policies are the rules that determine how traffic is allowed or denied between these segments and layers.

Q: How are firewalls different from microsegmentation?

A: Firewalls control access to a network by filtering traffic based on predefined rules. While firewalls can be used to control access between segments, microsegmentation divides a network into smaller segments and applies unique security policies to each segment. This provides a more granular level of control over network access, allowing organizations to limit access to specific applications and services.

Q: What is a virtual network?

A: A virtual network operates within a physical network infrastructure but uses software to connect computers, VMs, and servers or virtual servers over a secured network. This is in distinction to the traditional physical network model where hardware and cables connect network systems. Virtual networks can be used to create isolated environments within a larger network, allowing organizations to microsegment specific applications or services.

Microsegmentation can help organizations better protect their applications and data in their networks from potential threats, as it limits the attack surface available to an attacker. In addition, microsegmentation can provide greater visibility and control over network traffic, making it easier to identify and respond to security incidents.

F5 offers products and services that can help organizations implement and manage microsegmentation and other security controls in their networks. Learn how F5 delivers simple and secure connectivity across public and hybrid clouds, data centers, and edge sites. Explore how F5 provides app layer secure networking and automated cloud network provisioning for enhanced operational efficiency