NordLayer - Network Security

What is Network Access Control, and why is it important?

By NordLayer
1 Mar 2022
9 min read
What is Network Access Control

Business networks are changing rapidly, causing new threats to emerge and creating unknown risks that network managers need to consider.

Remote working is now routine, with around 45% of Americans working at home full-time or part-time. Cloud storage accounts for approximately 50% of corporate data worldwide, while the number of IoT-connected endpoints reached 12.3 billion in 2021, and projections suggest it will reach 27 billion by 2025.

These changes have made it vital to secure network devices and control perimeter access. Network Access Control (NAC) is one solution to this problem, but what is it, and how can companies benefit from NAC implementations? Let’s find out more.

What is Network Access Control (NAC), and what does it aim to achieve?

The name “Network Access Control” is almost self-explanatory. At its simplest, NAC solutions provide a way to manage access to network resources. It makes all devices and users visible to network managers and allows technicians to enforce security policies across every part of corporate networks.

Network Access Control generally includes tools that authenticate and authorize network users to access specific resources. These fundamental capabilities combine with threat response methods, including quarantine, access denial, or restricted access.

NAC isn’t wholly new. Standards like IEEE 802.1X and WPA have protected networks for decades. However, NAC solutions transcend older methods, providing security tools relevant to distributed, constantly changing networks linked to IoT and Cloud resources.

NAC systems allow companies to set finely calibrated access policies when implemented correctly. They can determine exactly how each user moves around networks and which resources they can access. They can monitor users and devices for threats and eliminate malicious actors before they cause damage. And they can do so without compromising efficiency or convenience.

What are the advantages of network access control?

  • Facilitates user network access orchestration

  • Allows resource access management

  • Gives the option to restrict guest network access

  • Enables user segmentation based on roles

  • Helps to detect suspicious activity

  • Supports incident response automation

  • Contributes to regulatory compliance

By implementing network access control, organizations can enhance their network security, mitigate risks, and ensure that only authorized users and devices have access to the network and its resources. As a result, NAC solutions provide additional advantages beyond those listed above, such as increased network visibility, improved cybersecurity posture, and more effective compliance with security regulations.

Increased network visibility

The expansion of remote working, BYOD, third-party collaborations and IoT connectivity poses severe problems for network managers. The proliferation of devices and users is hard to map and monitor, making complete network visibility challenging to achieve. NAC solutions solve this issue by mapping every device that connects to a network and implementing policies covering every authorized user.

Improved cybersecurity

The threat from cyberattacks grows constantly. Corporate resources are exposed to malware, ransomware, and DDoS attacks, while hackers continuously seek access to sensitive data that they can sell on the Dark Web. NAC solutions minimize these threats by excluding unauthorized or suspicious actors and limiting what users can do to achieve network access.

More effective compliance

Regulators are becoming stricter about how companies protect client information, especially where payment and personal information are concerned. Companies with solid records of compliance with security regulations benefit from a trust dividend and reduce the risk of losses associated with data theft. NAC can assist with both tasks by following gold-standard security compliance across all network endpoints.

How does Network Access Control work?

Network access control scheme

NAC solutions function by establishing which devices and users are authorized to connect to wired and wireless networks. Security teams devise a protocol that forms the basis of authorization policies, and specialist software applies those protocols every time a connection request is received.

NAC systems refer to third-party authentication services when they receive access requests and establish user permissions. When the system authenticates users, it creates secure connections that resemble classic Virtual Private Network (VPN) tunnels.

NAC tools may also determine which resources are available to corporate network users. Security policies can set out different access tiers dependent upon user roles, and NAC software can make it impossible for users to move outside their allotted permissions.

This architecture provides several capabilities for network managers, making threat management much more manageable.

Capabilities of Network Access Control

Total network visibility

NAC implementations make networks more legible for corporate network managers. Security teams can map out what devices are connected and the contours of the network perimeter. They can identify threats and launch mitigation actions based on this information before they cause any damage.

Instant user profiling

When users request remote access to NAC portals, the system immediately checks their credentials. NAC software can exclude unknown devices and individuals by comparing this data with centrally held resources.

Guest networking management

Network Access Control solutions also allow companies to admit guest users securely. Secure guest access makes it possible to collaborate with partners and contractors while keeping security threats low.

Internal access management

When corporate networks grant user access, NAC tools determine what they can do. Sensitive resources like client databases can be kept off-limits to unauthorized users. Malicious actors will also struggle to move laterally throughout networks, limiting the dangers posed by malware attacks.

Network management

In some cases, NAC tools can assist with network management tasks such as load balancing and resource allocation. The need to update admission policies also encourages regular protocol monitoring, prompting security teams to update access strategies.

What are the major NAC use cases?

Managing BYOD work arrangements

Remote working, mobile devices, and Bring-Your-Own-Device practices have become much more common in recent years. That’s good news for flexible working and collaboration but potentially leads to expanded threat surfaces and network management issues. NAC allows security teams to log BYOD authorizations and only authenticated devices to access resources.

Safe collaboration with corporate partners

Working with contractors, guests, and external partners is a regular part of modern work. But network security problems can arise when you bring in third parties to access corporate resources. NAC solutions work around this by authorizing third parties seeking access to your data, allowing efficient collaboration without posing undue risks.

Incident response

When cyberattacks happen, NAC can spring into action. Companies can set up NAC applications to deliver threat response data to third-party security partners, facilitating immediate mitigation measures. Any endpoints affected by attacks can be neutralized and quarantined, and lateral movement throughout networks can be restricted.

Handling IoT-based systems

The Internet-of-Things has become a vital tool for companies in diverse sectors, with IoT devices like automated equipment, sensors, smart grids, and even IoT-connected vehicle fleets all featuring. NAC can connect large numbers of IoT devices securely and systematically, ensuring that no rogue devices are left unmapped — also applying to the proliferation of medical devices connected to the IoT. Flows of sensitive data can be regulated and protected via adaptive NAC solutions.

Security compliance

NAC is also a valuable tool to ensure compliance with relevant cybersecurity regulations. Network security policies can be integrated into GDPR or HIPAA compliance plans, providing evidence that networks meet external standards.

What are the main types of Network Access Control solutions?

There are many NAC packages around and an almost infinite number of ways to configure them. However, it helps to simplify things by dividing them into two major types:


Pre-admission NAC technology assesses, authenticates, and admits users when they seek to connect with corporate networks. Everything happens before users obtain access. This system stores user credentials on secure databases and access protocols specify requirements that devices need to meet before entry is permitted. Third-party authentication services are generally also used to provide extra assurance via MFA.


Post-admission NAC is a little different. In this case, pre-admission authentication may remain. However, post-admission network security infrastructure monitors what users can do once they access corporate resources. Internal firewalls segregate network resources, while security protocols ensure users only access data corresponding to their privileges. When endpoints try to breach those privileges, post-admission NAC systems will shut them down and deny access.

Why is it essential to have a Network Access Control solution?

Network perimeters continue to expand and mutate. Edges are becoming more chaotic and unpredictable as increasing mobile devices connect from multiplying locations. Threat surfaces have also expanded, posing significant threats to companies that fear data theft and other forms of cyberattack.

That’s why Network Access Control is crucially important. Individual and corporate data has never been more critical, yet the world has never been more connected. This connectivity leaves networks acutely vulnerable to attacks, while managers must meet increasingly complex compliance requirements.

NAC offers a simplified route to compliance while locking down sensitive resources and ensuring network access for those who need it.

How to implement NAC solutions

The benefits of installing a form of Network Access Control are clear, but how should companies go about doing so?

Methods vary depending on the contours of each network, the number of IoT and third-party devices involved, the budget of the company, and the decision to choose pre-admission, post-admission, or hybrid network security solutions. But some basic steps are common to most NAC applications.

  • Firstly, security teams should map and log all endpoint devices connected to the network. Carry out a comprehensive survey of network edges, taking into account IoT devices, employee devices like laptops, and centralized equipment.

  • Security teams now need to create a Network Access Control List. This list includes details of all authorized users, along with their level of permitted access. Start by recording all user identities on a central database. Using the existing network directory is usually a sound basis for this stage.

  • Next, decide how to grant permissions to authorized users. To save time and simplify the process, it makes sense to establish permissions by role instead of on an individual basis. Try to apply the principle of least privilege (PYOP) wherever possible. PYOP means giving users enough freedom to access what they need while limiting everything else.

  • Set up the technology required to implement your Access Control List. Test the access portal to ensure that relevant users can obtain access and that systems exclude unauthorized users.

  • Finally, create and maintain systems to update the NAC system as required. Access Control Lists will change as network layouts change. Applications will need regular updates to ensure that antivirus, access control, and encryption technologies are up to date.

Following these steps should allow companies to create secure network access systems. But it isn’t usually wise or necessary to do so alone. Many NAC providers can supply expertise and technology to develop customized network security solutions.

NordLayer offers a comprehensive suite of products to lock down networks along with Zero Trust principles. Our NAC solutions can balance availability and security, guarding essential resources against cyberattacks and allowing users to work efficiently. Solutions can be adapted for any network architecture, incorporating cutting-edge encryption and authentication processes.

Discover more by contacting our team. We’ll help you do whatever it takes to achieve network security enforcement and deliver simplified access for the people that matter.

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