What is Network Access Control (NAC)?

January 8, 2024

With the many cybersecurity threats lurking in the shadows as our businesses become increasingly digitised, it is vital to invest in the right modes of defence. Network Access Control (NAC) stands out as a crucial asset in reinforcing your company’s security. In this article, we will explore the practical importance of NAC for your business, examining its key functions and strategic implications in countering cyber threats.

What exactly is network access control?

NAC acts as a frontline defence tool against unauthorised access and potential security breaches. At its core, NAC is a comprehensive approach to managing and securing network endpoints by regulating the access granted to devices and users. It provides a powerful framework for your business to authenticate, authorise, and evaluate devices seeking entry to your network.

By enforcing strict access policies, NAC ensures that only approved and compliant devices gain entry, reducing the risk of malicious activities and fortifying the overall security posture.

Why does network access control matter for your business?

NAC's multifaceted approach functions on two main levels. These address risks both from external sources and within your organisation:

1. It prevents unauthorised access to networks from outsiders: By implementing sophisticated authentication methods and strict access policies, NAC acts as a formidable barricade, safeguarding against potential data breaches and system compromise. With cyber threats constantly progressing, NAC serves as a proactive barrier, making it challenging for malicious actors to infiltrate networks and exploit vulnerabilities.

2. It mitigates insider threats: NAC is equally vital in addressing insider threats. By providing control over user access privileges and enforcing the principle of least privilege, NAC minimises the impact of internal actors with malicious intent. Continuous monitoring capabilities enable real-time detection of anomalous behaviour, enhancing your business’s ability to respond promptly to potential insider threats.

Network access control and incident response

NAC plays a key role in incident response by facilitating rapid threat containment. When a security incident occurs, NAC acts as a frontline defence mechanism, automatically restricting access for the affected user or device. By isolating the compromised entity from the network, NAC prevents the lateral movement of threats and limits their impact on critical systems. This swift containment minimises the scope of the incident, allowing security teams to focus on investigation, remediation, and preventing further escalation. NAC's integration with incident response plans significantly enhances your business’s ability to respond effectively to cybersecurity threats.

Key components of network access control

  • Endpoint authentication

At the core of NAC lies endpoint authentication. This fundamental component ensures that devices seeking access to the network are first authenticated before being granted entry. By employing multifaceted authentication methods such as certificates, biometrics, and user credentials, you can verify the legitimacy of each endpoint, reducing the risk of unauthorised access. Endpoint authentication not only fortifies the network perimeter but also establishes a secure foundation for comprehensive access control.

  • Access control policies

Effective NAC relies on well-defined access control policies that govern the permissions granted to devices and users within the network. These policies, rooted in the principle of least privilege, dictate the specific resources and services accessible to each employee and guest based on their role and responsibilities. Solid access controls minimise potential attack surfaces and mitigate the impact of security incidents.

  • Automated threat response

Automated threat response involves implementing predefined actions to address security incidents promptly. This includes the automatic isolation of compromised devices or the restriction of their access upon detection of suspicious activities. By integrating automated responses, your business can significantly reduce response times, limit the potential impact of security incidents, and minimise the manual intervention required during threat mitigation. This proactive approach is crucial for maintaining the integrity and security of the network.

  • Integration with security information and event management (SIEM)

Integrating NAC with SIEM (threat detection) means working with SIEM platforms to collect and analyse security event data comprehensively. SIEM systems gather data from various sources, connect events, and offer insights into potential security threats. This integration helps improve threat detection, streamline incident response, and provide a comprehensive view of the security landscape. Utilising SIEM capabilities is key to identifying patterns, anomalies, and vulnerabilities, enabling a more effective and proactive cybersecurity approach.

  • Educational initiatives

The effectiveness of any cybersecurity measure is undermined when your team is unaware of security risks and the systems you have put in place to mitigate them. User training and awareness programs educate employees about essential security practices and the significance of adhering to access policies. These initiatives cover the importance of strong passwords and the role employees play in maintaining a secure network environment. By fostering a culture of cybersecurity awareness, you will empower your team to recognise and mitigate potential risks, contributing to an overall resilient security posture.

  • Continuous monitoring and compliance

Network security is an ongoing endeavour, and NAC addresses this by incorporating continuous monitoring and compliance as key components. Through real-time monitoring of device behaviour and adherence to established access policies, NAC systems can promptly detect and respond to any deviations or security anomalies. Additionally, by ensuring continuous compliance with security standards and regulations, NAC helps your business uphold a proactive security posture.

What are the benefits of implementing NAC?

  • Strengthening network security

The primary benefit of implementing NAC is the fortification of network security. NAC acts as a robust defence mechanism against unauthorised access, reducing the risk of data breaches and cyber threats. By enforcing strict access controls and authentication measures, your business will create a resilient security perimeter that safeguards sensitive data and critical infrastructure.

  • Enhancing visibility and control

NAC brings enhanced visibility and control over network activities. Through comprehensive monitoring and reporting features, you gain real-time insights into user and device behaviour. This heightened visibility enables quicker detection of suspicious activities, allowing for prompt response and mitigation. The control afforded by NAC ensures that access privileges align with business policies, reducing the potential for security lapses.

  • Automated incident response

NAC streamlines incident response through automation. In the event of a security incident, automated responses can be triggered swiftly, reducing the time between detection and mitigation and minimising potential damage.

  • Employee segmentation and role-based policies

NAC allows you to segment employees based on job functions and establish role-based access policies. This tailored approach ensures that individuals have access only to the resources necessary for their roles, reducing the risk of insider threats and unsanctioned activities.

  • Adaptable network entry for external entities

NAC provides your business with the ability to permit entry for contractors, partners, and guests as needed, all while limiting their access to designated resources. This flexibility fosters collaborative efforts without compromising the overall security posture of your network.

  • Regulatory compliance

Implementing NAC facilitates adherence to regulatory compliance requirements. Many industries and regions have specific data protection and security standards that companies must meet. NAC assists in ensuring that network access and user activities align with these regulations. By automating compliance checks and maintaining audit trails, you can not only meet regulatory obligations but also demonstrate a commitment to effective cybersecurity practices. The alignment of NAC with regulatory frameworks is instrumental in building trust with stakeholders and avoiding legal repercussions.

Challenges in network access control

A significant challenge in NAC is striking the right balance between stringent security measures and user convenience. While robust security protocols are crucial for threat prevention, overly complex authentication processes can hinder user productivity. Achieving this balance requires the implementation of effective security measures without causing unnecessary friction for users, for a comfortable yet secure access experience.

Another challenge arises in the integration of NAC with diverse network environments. Many businesses operate with a mix of legacy and modern systems, posing difficulties in harmoniously deploying NAC solutions across the entire infrastructure. The presence of compatibility issues, differing protocols, and varying network architectures requires careful planning and integration strategies.

Network access control deployment strategies

To customise NAC to your business infrastructure, you will generally have a choice between three deployment schemes:

1. On-premises NAC solutions

This involves putting access control and security measures in place directly within your company’s physical set-up. This strategy offers you direct control over the NAC system, ensuring data stays within the premises and allowing for tailored configurations. On-premises NAC solutions are often favoured by businesses with strict security and compliance requirements, as they provide a centralised approach to network security.

2. Cloud-based NAC solutions

Cloud-based NAC solutions operate on remote servers, offering flexibility and scalability. With cloud-based NAC, you benefit from reduced infrastructure costs and improved accessibility, as the system is accessible from anywhere. This approach is particularly advantageous if your business has distributed teams and if you want to leverage the scalability and efficiency of cloud technologies.

3. Hybrid approaches

Hybrid NAC combines on-premises and cloud-based solutions to provide maximum flexibility. You can maintain control over critical aspects of security while taking advantage of what the cloud has to offer. This is suitable for businesses with dynamic needs, offering a customised approach that adapts to the growing requirements of the network infrastructure.

Network access control best practices

To optimise the effectiveness of NAC, it is important to consider the following elements:

  • Establishing comprehensive access policies

Clear and well-defined access policies dictate who can access the network, what resources they can access, and under what conditions. These policies should align with your company’s security objectives and industry compliance standards. By enforcing strict access controls based on roles and responsibilities, you can mitigate security risks and maintain a strong defence against unapproved access.

  • Regular audits and updates

Regular assessments of your NAC system ensure it remains aligned with the most recent security requirements and compliance standards. This involves reviewing access policies, evaluating system logs for anomalies, and updating software to address emerging threats. Regular audits and updates are integral to the proactive maintenance of a secure network environment, enhancing the overall effectiveness of your NAC solution.

  • Training and awareness for users

We have already mentioned the importance of employee education for successful NAC implementation. Providing training on secure practices, password management, and the consequences of non-compliance enhances user awareness and reduces the likelihood of security incidents. A well-informed user base contributes significantly to the overall efficacy of your NAC system by fostering a culture of security within your business.

Future trends in network access control

Two upcoming trends will largely influence the future trajectory of NAC. Firstly, the Zero Trust Security Model is gaining prominence. Zero Trust emphasises the principle of "never trust, always verify," treating every user and device attempting to access the network as untrusted, regardless of their location. NAC cooperates consistently with Zero Trust by providing continuous authentication and authorisation based on device health and user behaviour. As businesses increasingly adopt Zero Trust Security to address growing cyber threats, the integration with NAC becomes pivotal in establishing a comprehensive and adaptive security posture.

Secondly, the future of NAC is closely tied to advancements in Artificial Intelligence (AI) and Machine Learning (ML). AI and ML technologies are being leveraged to enhance the capabilities of NAC systems in terms of threat detection, anomaly analysis, and automated response. These technologies enable NAC solutions to identify patterns and trends in user behaviour, detect previously unknown threats, and automate responses to security incidents in real time. By incorporating AI and ML, NAC systems become more adaptive and efficient in addressing the dynamic and sophisticated nature of modern cybersecurity threats, marking a crucial trend in the evolution of network security protocols.

Choosing the right network access control solution

When evaluating NAC providers, you must prioritise the comprehensiveness of the solution on offer. Be sure that it lines up with your business’s specific security needs, offering strict authentication methods, strong access controls, and logical integration with existing systems.

Scalability is a fundamental factor in your selection process. Companies undergo changes and expansions over time, and so an NAC solution must be scalable to accommodate increasing numbers of devices and users. It should handle growth without sacrificing performance or security.

Future-proofing is equally vital. Your NAC solution should demonstrate flexibility in adapting to emerging technologies and evolving security threats. This includes the ability to smoothly integrate with new devices, applications, and security protocols that may become relevant in the future.

Be sure to also assess an NAC provider’s reputation, track record, and customer reviews. A provider with a proven history of delivering effective NAC solutions and providing reliable customer support is more likely to meet your business’s long-term security needs.

Implementing network access control | Steps and challenges


1. The first step to successfully implementing NAC is to conduct a comprehensive assessment of your network infrastructure, identifying existing security policies, potential vulnerabilities, and the specific requirements of your business. Once these are clarified, define clear objectives for the NAC deployment, such as enhancing overall security, controlling user access, or ensuring regulatory compliance.

2. Establish a cross-functional team comprising IT, security, and relevant business units to ensure a holistic approach.

3. Conduct a thorough inventory of devices and users on the network to inform access policies.

4. Define access control policies based on job roles and responsibilities, applying the principle of least privilege.

5. Implement the chosen NAC solution gradually, starting with a pilot phase to identify and address any issues before full-scale deployment.

6. Provide comprehensive training to users and IT staff to ensure a smooth transition, and continually monitor and update the NAC system to adapt to evolving security needs.


Despite its benefits, implementing NAC may face challenges. One common challenge is resistance from end-users, particularly if the implementation introduces changes to their accustomed workflows. You can overcome this by fostering communication and providing clear explanations of the benefits.

Integration with existing network infrastructure can be another challenge, requiring careful planning to avoid disruptions. Be sure to collaborate closely with IT teams, conduct thorough testing, and gradually roll out the implementation.

Finally, see to it that the NAC system makes sense in the context of your business’s specific requirements and industry regulations to overcome compliance challenges.

Measuring network access control effectiveness

Testing the effectiveness of NAC is essential to ensuring its ongoing success in your cybersecurity strategy.

Determining the right key performance indicators (KPIs) for NAC involves aligning them with the security objectives you have for your business. Some KPIs you may consider include the percentage reduction in security incidents related to unauthorised access, the speed of incident response times, and the level of compliance with access policies. Monitoring the number of devices and users successfully authenticated and the accuracy of threat detection also provides valuable insights. By focusing on these KPIs, you can measure the tangible impact of NAC on your business’s security posture, enabling informed decision-making.

Continuous improvement is vital for the long-term efficacy of NAC strategies. Regularly reviewing and updating access policies is crucial. Conducting periodic audits of the NAC system to ensure alignment with industry regulations and company policies helps identify and address potential vulnerabilities. Additionally, staying informed about emerging cybersecurity threats allows you to proactively adjust your NAC strategies to mitigate new risks. Establishing a feedback loop that incorporates lessons learned from security incidents and user feedback contributes to an adaptive and resilient NAC framework, fostering continuous improvement in overall cybersecurity.

Final thoughts

NAC is a pivotal tool in fortifying network security. It regulates access, authenticates users, and protects against unauthorised entry. The dynamic nature of modern threats requires businesses to adopt comprehensive measures, and NAC emerges as a foundational component in this defensive strategy. By continually assessing its effectiveness, aligning with industry best practices, and adapting to emerging challenges, you can empower your network security with NAC, reinforcing its resilience against cyber threats.

Our team at ITRS is here to help with the process! We are passionate about creating safe and stable IT environments for businesses. Contact us to find out how we can partner with you to transform your business’s cybersecurity posture.

Back to blogs
Three planes flying in formation

ITRS = Business - Risk ²

These powerful solutions can be tailored to meet the unique requirements of your business.
If you would like to learn more about how your company can benefit from a more agile approach, greater ease of use and flexibility, secure cloud infrastructure services from ITRS are the answer.

Get started today
Search Website