What is Network Access Control?

Network Access Control (NAC) is a centralized approach to end-point security that focuses on network visibility and restrictive access management by enforcing policies across all users and devices. NAC intends to do exactly what its name implies: control network access. The goal of Network Access Management is to prevent unauthorized devices or users from entering a private corporate network.

 

Network Access Control provides visibility, access control, and security for corporate networks. Network Access Control assists organizations in identifying and implementing strict controls for access management, compliance with safety regulations, reducing manual labor, and preventing data breaches.

 

 

What is Network Access Control? 

 

The process of preventing unauthorized users and devices from gaining access to a corporate or private network is known as Network Access Control (NAC). NAC ensures that only authenticated users and devices that are authorized and in compliance with security policies can access the network.

 

More control is required as endpoints proliferate across an organization, typically as a result of bring-your-own-device (BYOD) policies and an increase in the use of Internet-of-Things (IoT) devices. Even the most potent IT departments lack the resources to manually configure all of the devices in use. The automated features of a NAC solution are a significant benefit, as they reduce the time and costs associated with authenticating and authorizing users and determining that their devices are compliant.

 

Furthermore, cybercriminals are well aware of the rise in endpoint usage and are continuing to design and launch sophisticated campaigns that exploit any vulnerabilities in corporate networks. With more endpoints, the attack surface expands, giving fraudsters more opportunities to gain access. NAC solutions can be set up to detect unusual or suspicious network activity and take immediate action, such as disconnecting the device from the network to prevent the attack from spreading.

 

Although IoT and BYOD have altered NAC solutions, NAC still serves as a continuous inventory of users, devices, and access levels. It acts as an active discovery tool, detecting previously unknown devices that may have gained access to all or parts of the network, necessitating further investigation.

 

Furthermore, organizations can specify how NAC will authenticate users attempting to access the network. IT administrators can use multi-factor authentication (MFA) to add an extra layer of security to username and password combinations.

 

Restricting network access entails control over the applications and data on the network, which is typically the target of cybercriminals. The stronger the network controls, the more difficult it will be to infiltrate the network.

 

Also Read | What is Network Security

 

How does Network Access Control Work?

 

Using a set of protocols and policies, Network Access Control is a tool that defines and implements rules that specify which users and devices can access the network. In most cases, a NAC system is designed to prevent non-compliant and unauthorized devices from accessing the network.

 

NAC allows you to deny or allow network access based on a variety of factors such as system health or role-based variables. NAC assists in identifying and enforcing network access policies based on company tasks. As a result, NAC should be configured so that employees only have access to the information needed to perform their job functions.

 

NAC consists of two stages: authentication and authorization. If either stage fails, the device or user is blocked and quarantined.

 

During authentication, the NAC system prompts the user to enter credentials to confirm their identity as an authorized user. Companies can use various authentication methods such as username or password, pin, biometric scan, and so on.

 

Following authentication, NAC approves access based on local access policies. Access is granted if the user or computer is authorized by the access policies. Otherwise, access is denied.

 

NAC is critical for modern businesses because it allows organizations to monitor the devices and users attempting to access the network, both authorized and unauthorized.

 

Unauthorized users include cybercriminals, hackers, data thieves, and other bad actors that must be kept out of an organization. However, businesses must also serve as gatekeepers for authorized users. This is especially true for organizations that allow non-corporate devices such as mobile phones, laptops, and tablets to connect to the enterprise network, or for companies that allow employees working in the office to use personal devices. Both scenarios pose security risks, necessitating organizations' attention to network security.

 

Also Read | What are Cyber-Physical Systems 

 

Key Components of Network Access Control: 

 

Network access control is in charge of a large number of computing systems, both on-premise and remote. As a result, it includes a meticulously designed solution architecture, with each component contributing to security enforcement, maintenance, and remediation. An industry-standard network access control solution includes the following components:

 

1. Client :

 

Customer Endpoint systems, also known as clients, are critical components of network access control. These are the most commonly used windows for network access, data exchange, and general computing activities. Because there are deep connections between devices and on-premise servers, endpoint vulnerabilities could cripple the entire enterprise network.

 

Clients include physical endpoints such as computers, laptops, connected printers, IP phones, and so on, as well as virtual machines where you may be hosting a workstation.

 

2. Client- Software:

 

In addition to the entire computing system, an access gateway is sometimes identified as a specific application or set of applications. In these cases, the client's software application is also regarded as a component of the network access control architecture, actively participating in the authentication and security enforcement processes.

 

3. Authentication server:

 

One of the most important components of network access control is the authentication server. The credentials of the client device or client software requesting access are typically validated by a physical server of the remote authentication dial-in user service (RADIUS) variant.

 

Most network access control solutions validate these credentials using a list of named entities such as usernames, passwords, and digital certificates. Context and behavior-based authentication are also used in more advanced solutions. This component is hosted on a public cloud for a cloud-based network access control solution.

 

4. Authenticator:

 

The authenticator facilitates authentication between the client (device or software) and the authentication server. It consists of a managed switch or access point that securely relays credentials between components 1 or 2 and 3, ensuring that a port remains labeled as untrusted until authentication occurs. Once the server has given the go-ahead, the authenticator is in charge of changing the port's state to "authorized."

 

5. Framework for authentication:

 

The authentication framework is the language in which credentials are exchanged between the client device, client software, authentication server, and authenticator. It varies depending on the solution; for example, if you need to configure multiple authentication methods into the system, you can use extensible authentication protocol (EAP) or EAP over LAN (EAPoL) as the framework.

 

6. Guest networks:

 

To isolate all third-party traffic, organizations may implement a dedicated guest network. This is relevant for enterprises operating from the same enterprise premise with a large non-payroll workforce and multiple third-party stakeholders such as regulatory bodies, consultants, vendors, etc. Guest networks are a common component of cloud-hosted network access controls that govern third-party remote access.

 

Use cases of Network Access Control:

 

NAC tools are proactive in nature, designed to prevent unauthorized access before it occurs. They safeguard a company's network perimeter, which includes physical infrastructure, devices, software, applications, and cloud-based assets.

 

NAC has numerous applications:

 

1. BYOD: With the exponential proliferation of mobile devices, workers have been liberated from their workstations and are now able to work remotely on their mobile devices. NAC for BYOD ensures compliance for all employee-owned devices prior to network access.

 

2. Incidence Response: NAC suppliers provide contextual information (such as user ID or device type) to third-party security components. In response to cybersecurity alerts, they automatically enforce security rules that isolate infected endpoints.

 

3. Visitors and Partners: Organizations use NAC solutions to ensure contractors, guests, and partners have separate network access credentials than employees. VPNs have traditionally been used by businesses to provide secure encrypted connections for remote access to the corporate network for remote workers and contractors. A VPN does not prevent an endpoint from connecting to the network; it simply allows for remote network communication. A VPN cannot verify a user or prevent "unhealthy" devices from connecting to the network on their own. NAC can be built on top of a VPN, VDI, or other remote access techniques to provide effective authentication, access control, and endpoint risk profiling.

 

4. Internet of Things (IoT) devices are proliferating rapidly in manufacturing, healthcare, and other industries, providing attackers with more entry points into the network. By implementing specific access controls and device-specific profiling, NAC can reduce these risks in IoT devices.

 

5. Device Risk Position Assessment: The security of your business network is only as good as its most vulnerable security connection. As a result, constant risk assessment is required. Your network and security teams can thwart cyber attacks by identifying and responding to emerging threats in real-time by continuously monitoring the network. Continuous risk posture assessment must work regardless of location, device type, or data transport type in a world with ever-expanding borders and an exponential rise in endpoint types.

 

Network access control is a centralized approach to securing network access that enforces policies across all devices and users. NAC's primary goal is to prevent unauthorized devices or users from connecting to a private network. This is frequently accomplished through the use of zero-trust access solutions, which provide visibility into all devices on a private or corporate network.

 

Despite the fact that NAC technology has been around for nearly two decades, a new generation of solutions is now required to protect the modern, ever-expanding attack surface – one that has only grown more complex as the world has shifted to remote work. 

 

It can be concluded that it necessitates visibility into devices connecting from both inside and outside the network, as well as the ability to respond automatically when/if devices are compromised.

 

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