Cisco Network Admission Control

Definition of Cisco Network Admission Control

Cisco Network Admission Control (NAC) is a security feature that restricts access to network resources based on the compliance of connected devices with predefined security policies. It evaluates the security posture of these devices, ensuring that they meet the necessary criteria, before allowing them access. In simpler terms, NAC helps protect a network by allowing only compliant and trusted devices to access it.


The phonetics of the keyword “Cisco Network Admission Control” using the International Phonetic Alphabet (IPA) are:/’sɪskoʊ ‘nɛtwɜrk əd’mɪʃən kən’troʊl/

Key Takeaways

  1. Cisco Network Admission Control (NAC) improves network security by allowing organizations to authenticate, authorize, and evaluate the security posture of all devices that attempt to access the network.
  2. With NAC, administrators can set security policies that prevent devices with outdated software, missing patches, or compromised configurations from accessing the network, thereby reducing the risk of security breaches.
  3. By integrating with other Cisco security solutions and third-party applications, NAC provides a flexible, comprehensive approach to network security that can adapt to evolving threats and changing business requirements.

Importance of Cisco Network Admission Control

Cisco Network Admission Control (NAC) is important because it provides a foundational layer of network security by ensuring that all devices connecting to a network are compliant with an organization’s security policies.

By verifying the endpoint device’s security status, such as antivirus and operating system updates, NAC restricts dangerous or vulnerable devices from accessing the network.

It also provides remediation measures for non-compliant devices, allowing them to be updated automatically, reducing the likelihood of security breaches.

By doing so, NAC plays a crucial role in fortifying an organization’s network, which is critical in today’s world where increasingly sophisticated cyber threats pose significant risks to sensitive data and business operations.


Cisco Network Admission Control (NAC) serves as a crucial component in maintaining and securing network infrastructure for organizations and enterprises. The primary purpose of NAC is to ensure that only authorized users and devices can access the network’s resources, while simultaneously detecting and mitigating any security threats that may arise.

Through its robust capabilities, NAC facilitates comprehensive visibility and control over all devices connecting to the network, helping administrators enforce security policies and maintain a consistently high standard of network security. To achieve this, Cisco Network Admission Control employs various techniques like authentication, inspection, and profiling.

It verifies users and devices for compliance with predefined security policies, including up-to-date anti-virus software, necessary patches, and system settings. When non-compliant devices are identified, NAC can either block them from accessing network resources or quarantine them in a limited-access environment until they undergo remediation.

This proactive approach to security management minimizes organizational vulnerabilities, ensuring greater resilience against cyber-attacks and maintaining a secure and streamlined network environment for all.

Examples of Cisco Network Admission Control

Cisco Network Admission Control (NAC) is a security solution that helps organizations protect their networks by restricting and managing the access of various devices. It evaluates the compliance of connected devices with predefined security policies and ensures that only compliant, secure devices are granted access to the network. Here are three real-world examples of Cisco NAC implementation:

Healthcare Sector: A large hospital with a growing number of mobile devices used by doctors, nurses, and other staff implemented Cisco NAC to secure their network. NAC was able to control the access of these devices, ensuring that only authorized users and devices with up-to-date security protocols could access sensitive patient data. This significantly reduced the risk of data breaches and the chances of malware entering the hospital’s network.

Financial Institution: A multinational banking corporation needed to protect its network from numerous cyber threats while managing regular access requirements for thousands of onsite and remote employees. By deploying Cisco NAC, they ensured that only authorized users and compliant devices could access their network infrastructure. This reduced the possibility of security breaches, allowing the institution to maintain customer trust and avoid potential financial losses due to cyberattacks.

University Campus: A large university deployed Cisco NAC to secure its network across the campus, which was being accessed by thousands of students, staff, and faculty members using various devices. NAC helped the university enforce policies, such as making sure devices were running up-to-date antivirus software and had the latest security patches installed. Furthermore, it allowed the IT team to identify and isolate devices that did not comply with these policies, preventing potential security breaches and keeping the network safe for all users.

Cisco Network Admission Control FAQ

What is Cisco Network Admission Control?

Cisco Network Admission Control (NAC) is a security solution that helps protect networks from potential threats by restricting access to devices that comply with security policies. It identifies, isolates, and prevents non-compliant devices from gaining access to the network, which helps ensure a secure, reliable environment for all connected devices.

How does Cisco Network Admission Control work?

Cisco NAC works by examining each device attempting to access the network and evaluating its security compliance. This compliance check may include verification of operating system patches, antivirus signatures, and other security components. If the device is deemed compliant, it is granted access to the network. If non-compliant, it may be quarantined, denied access, or provided limited access depending on the enforcement options configured.

What are the benefits of implementing Cisco Network Admission Control?

Implementing Cisco NAC offers several benefits, including increased network security, protection against unauthorized devices, reduced risks associated with malware and viruses, improved awareness and visibility of devices on the network, and centralized management of security policies for streamlined administration.

Which devices are compatible with Cisco Network Admission Control?

Cisco NAC supports a wide range of devices, including Cisco switches, routers, security appliances, and wireless access points. It can also work with third-party devices compliant with Cisco’s standards. To ensure compatibility, it’s essential to verify the specific devices in your network against Cisco’s compatibility matrix or consult with a Cisco representative.

Can I deploy Cisco Network Admission Control on an existing network?

Yes, Cisco NAC can be deployed on an existing network. It is designed to be flexible and scalable, making it suitable for various environments and network sizes. However, proper planning and assessment are required to ensure a smooth implementation and to avoid potential issues during deployment.

Related Technology Terms

  • Cisco Identity Services Engine (ISE)
  • Network Access Control (NAC)
  • Posture Assessment
  • 802.1X Authentication
  • Endpoint Security

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