Network Security Controls

What Are Network Security Controls?

They are protective measures and protocols put in place to defend an organization’s IT infrastructure from unauthorized access, misuse, malfunction, destruction, or improper disclosure. These controls are designed to detect, prevent, and respond to threats that could impact network integrity, confidentiality, or availability. They serve as the backbone of any cybersecurity strategy by establishing barriers and monitoring systems across network devices, systems, applications, and data.

These controls can be hardware-based, software-based, or a combination. They operate at different levels of a network—such as endpoints, applications, servers, and communication pathways—to ensure holistic protection. Examples include firewalls, intrusion detection systems (IDS), endpoint protection platforms (EPP), and identity and access management (IAM) tools.

 

Why Are They Important?

Modern organizations rely on increasingly complex, distributed, and internet-connected infrastructures. Without comprehensive network security controls, these environments are highly vulnerable to cyberattacks, malware, data breaches, insider threats, and operational disruptions. Here’s why robust controls matter:

• The cyber attack surface is expanding. As organizations adopt cloud computing, IoT, BYOD (Bring Your Own Device), and hybrid work models, they create more points of exposure for hackers to exploit. Reduce this surface by enforcing secure communication and access to the network and secure applications.

• Cyber threats are growing in sophistication. Threat actors use advanced tactics and advanced malware like ransomware-as-a-service, supply chain attacks, and AI-driven exploits of vulnerabilities. Without strong controls on the network and securing applications, it’s difficult to detect and respond to these evolving threats. Over the first half of 2025, there has already been: a 46% increase in zero-day exploits, a 36% increase in ransomware attacks, and an 80%  increase in published vulnerabilities to the CISA-KEV tracking system, per research from Forescout’s Vedere Labs.

• Regulatory and compliance pressures are intensifying. Laws such as GDPR, HIPAA, and PCI-DSS require strict data protection and authentication protocols. Controls help organizations meet these requirements by enforcing policies and generating audit trails.

• Downtime is more costly than ever. A successful cyberattack can cripple operations, damage reputation, and result in millions of dollars in losses. Consider that the average cost of a single hour of downtime exceeds $300,000 for over 90% of mid-size and large enterprises.[i] In fact, the total cost of downtime for Global 2000 companies has been pegged at $400 billion annually when digital environments fail unexpectedly.[ii] Controls like intrusion prevention systems (IPS) and endpoint protection reduce risk and recovery time.

• Zero Trust is now the gold standard. Adopting Zero Trust principles requires strong segmentation, continuous monitoring, and strict access controls, all of which are facilitated by well-implemented controls.

 

How Do Controls Relate to Network Security?

Network security is a broad discipline that encompasses the strategies, tools, and processes used to protect an organization’s digital infrastructure. The controls are the building blocks of this discipline. They provide the actual mechanisms through which policies are enforced, threats are mitigated, and access is managed.

For example, a network security policy might dictate that only employees from the finance department can access financial records. A network security control such as a firewall rule or role-based access control (RBAC) enforces this policy by technically restricting access.

More broadly, they support the three core goals of cybersecurity:

• Confidentiality: Ensuring only authorized users have access to sensitive information.
• Integrity: Protecting data from unauthorized alterations.
• Availability: Ensuring systems and data remain accessible to authorized, authenticated users.

 

How Do Controls Fit Into a Network Security Plan?

Network security controls are a foundational component of any comprehensive network security measures and plans. A network security plan outlines an organization’s strategy for protecting its digital infrastructure, network traffic, sensitive data, and communications from unauthorized access, misuse, disruption, or destruction. Within this framework, they serve as the tactical measures used to detect, prevent, and respond to threats.

Consider how to support the key objectives of a network security strategy:

• Identifying risks: Organizations select and implement controls based on the risk analysis that initiates the network security plan.
• Managing access: Controls enforce access policies by verifying identities, restricting permissions, and segmenting networks.
• Protecting infrastructure: Tools like firewalls, anti-malware, and intrusion prevention systems (IPS) help defend key systems and data outlined in the plan.
• Detecting and responding to threats: Intrusion detection systems (IDS), network monitoring, and analytics support real-time threat detection and response actions.
• Supporting compliance: Logging, reporting, and policy enforcement capabilities built into security controls help meet regulatory and audit requirements.
• Adapting to change: Configurable, intelligence-driven controls allow the plan to evolve with new threats and business needs.

In short, they are not standalone solutions. They are the mechanisms that execute and reinforce the strategies outlined in a network security plan. Without them, organizations cannot effectively enforce or maintain even the most well-documented plan.

 

Control Types

These controls are typically grouped into three categories:

1. Preventive controls: These are designed to stop threats before they happen. Examples include:
   • Firewalls
   • Network access control (NAC)
   • Encryptio
   • Patch management
2. Detective controls: These identify and alert teams about potential or actual security events. Examples include:
   • Intrusion detection systems (IDS)
   • Network monitoring tools
   • Security Information and Event Management (SIEM)
3. Corrective controls: These respond to and remediate incidents after detection. Examples include:
   • Incident response tools
   • Backup and recovery solutions
   • Automated containment systems

Controls can also be categorized as administrative, technical, or physical, depending on their scope and implementation.

 

Why Use a Combination of Controls?

A layered security approach—or defense-in-depth strategy—ensures that if one control fails, others remain in place to protect the system. Here’s why combining controls is essential:

• No single control is foolproof. Attackers often exploit gaps between isolated tools. Using overlapping controls improves overall resilience. A virtual private network or VPN is not enough.
• Threats operate at multiple layers. Attack vectors can target endpoints, edge devices, like firewalls and VPNs*, users, applications, or infrastructure. A combination of controls ensures full-stack protection.
• Security maturity varies across organizations. Different departments and systems may be at different stages of readiness. Combining controls allows organizations to tailor defense based on context.
• Compliance often requires it. Regulations typically mandate multiple layers of control—technical, physical, and procedural—to ensure comprehensive risk mitigation.
• Integrated controls enable faster response. When security tools work together, they can detect, isolate, and respond to incidents more effectively.

*Recent data from Forescout Research Vedere Labs shows VPNs are regularly targeted for application vulnerabilities today. In 2025, we have observed cybersriminals are increasingly using Initial Access Brokers (IABs) and exploitation of vulnerabilities in specific public-facing applications, including VPNs, remote access solutions, and file transfer applications.

 

Common Network Security Frameworks

Organizations often implement one or more formalized frameworks that provide guidelines and best practices. Here are several of the most widely adopted:

• NIST Cybersecurity Framework (CSF)[iii]: Provides a structured approach to identifying, protecting, detecting, responding to, and recovering from cyber threats. It aligns to measurable risk management goals.
• CIS Critical Security Controls[iv]: Offers a prioritized list of controls for stopping the most pervasive threats. It includes specific controls focused on network monitoring, secure configurations, and data protection.
• ISO/IEC 27001[v]: A globally recognized standard for information security management systems (ISMS). It defines requirements for implementing and continually improving controls across an organization, including networks. For instance, Annex A 8.20 of ISO 27001 focuses on preventing unauthorized access, ensuring secure data transmission, and monitoring network activities.
• COBIT® (Control Objectives for Information and Related Technologies)[vi]: This framework created by ISACA focuses on IT governance and management. It includes controls that ensure security aligns with business objectives and regulatory compliance.
• Zero Trust Architecture (ZTA): While not a traditional framework, ZTA is a design approach that assumes no user or device should be trusted by default. It promotes using continuous monitoring, access controls, and segmentation, which are all examples.

 

Common Challenges

Even the most well-designed controls can fall short without proper implementation, oversight, and adaptability. Here are some of the most common obstacles organizations face:

• Complexity of hybrid environments: Managing controls across cloud, on-prem, and IoT environments can lead to visibility gaps and inconsistent enforcement.
• Tool sprawl and poor integration: Organizations often use disconnected tools that don’t communicate, making it difficult to gain a cohesive security posture.
• False positives and alert fatigue: Excessive alerts from security tools can overwhelm analysts, causing them to miss genuine threats.
• Shortage of skilled talent: The cybersecurity workforce gap makes it hard to find professionals capable of implementing and maintaining effective controls.
• Changing threat landscape: They must constantly evolve to keep up with emerging threats, requiring continuous monitoring and updates.

 

Best Practices

Effective implementation requires planning, collaboration, and continuous evaluation. Here are some key best practices:

1. Conduct a risk assessment: Understand the organization’s most valuable assets and likely threats. Use this insight to prioritize controls that address the highest risks.
2. Use a framework for guidance: Choose a security framework such as NIST or CIS to help structure implementation. These provide proven models for deploying and maintaining controls.
3. Layer controls: Implement overlapping security measures to create a multi-tiered defense. Combine perimeter defenses with endpoint controls, identity protections, and network monitoring.
4. Automate where possible: Use automation to enforce policy, manage configurations, and respond to threats quickly. Automation helps reduce human error and operational overhead.
5. Continuously monitor and update: Security is not a one-and-done effort. Use continuous monitoring to detect new risks and update controls accordingly.
6. Test and audit regularly: Conduct penetration tests, vulnerability scans, and internal audits to ensure controls are working as intended and are aligned with compliance needs.
7. Foster a security culture: Train employees to understand and follow security policies. Human error is often the weakest link in any security program.

 

How Forescout Supports

Forescout delivers a platform that provides deep visibility, continuous compliance, and intelligent control for every connected asset. It helps organizations implement robust network security plans by:

• Identifying every device: Forescout discovers and classifies managed, unmanaged, and IoT/OT devices without requiring agents.
• Monitoring device posture: Continuously evaluates devices against security policies and compliance baselines.
• Enforcing access control: Applies dynamic policies based on role, behavior, and risk across IT, OT, IoT, and IoMT networks.
• Automating response: Integrates with firewalls, SIEM, NAC, and EDR tools to orchestrate real-time response.
• Segmenting the network: Enables software-defined segmentation and microsegmentation to reduce attack surface.
• Unifying visibility across hybrid environments: Provides a single view across on-prem, cloud, and edge environments.
• Supporting Zero Trust principles: Enables least-privilege access based on real-time device and user context, reducing attack surfaces and exposure to risk.
• Ensuring compliance with control frameworks: Provides audit-ready visibility and control across the network to align with standards such as NIST, CIS Controls, ISO/IEC 27001, and others.

See for yourself with a demo today.

---

[i] ITIC, ITIC 2024 Hourly Cost of Downtime Report Part 1, September 3, 2024

[ii] Splunk, The Hidden Costs of Downtime, Accessed July 17, 2025

[iii] NIST, The NIST Cybersecurity Framework (CSF) 2.0, February 26, 2024

[iv] Center for Internet Security, The 18 CIS Critical Security Controls, Accessed July 17, 2025

[v] ISO, ISO/IEC 27001:2022, Accessed July 17, 2025

[vi] ISACA®, COBIT An ISACA Framework, Accessed July 17, 2025