Network access control (NAC) prevents unauthorized users and devices from entering private networks. It also helps firms meet regulatory compliance standards.
The basics of NAC include:
Pre-admission endpoint security policy checks.
Post-admission re-authentication.
Restrictions on lateral movement inside a network to reduce cyber attack damage.
Pre-Admission Control
Network access control prevents unauthorized devices from connecting to the network. It ensures a machine can’t transmit malware into the organization’s data. It also guarantees that employees’ devices used for work comply with corporate security policies.
The types of network access control solutions provide pre-admission control based on traffic flow. These systems authenticate and authorize users and devices and quarantine non-compliant ones if necessary. They also enable organizations to determine the degree of network access they want their employees to have based on their roles and functions.
With BYOD policies and the proliferation of IoT, many organizations now have an expanded attack surface that includes third-party devices, IoT devices, and remote workers. NAC tools are designed to protect the physical infrastructure, applications, and cloud-based assets of a business network perimeter from cyber attacks.
To do this, an NAC solution may include a firewall, an intrusion detection system, and an anti-malware solution. It can also integrate with an organization’s other network security tools like network firewalls, security information and event management (SIEM), identity and access management (IAM), and advanced threat prevention to offer a holistic approach to security. It may also contain client-agent technology that empowers endpoints to self-assess their security posture and remove vulnerabilities as needed. It also manages the life cycle of an organization’s endpoints to pull them from the network as employees or devices no longer need them.
From physical barriers and access control systems to robust fire alarms and emergency protocols, building security weaves a protective web around a structure. It’s about deterring crime with well-lit exteriors and surveillance cameras, while also having intrusion detection systems ready to sound the alarm. But true security goes beyond technology.
Post-Admission Control
Network access control prevents unauthorized users and devices from entering a private network. It evaluates the security posture of each device and user and only grants access if they comply with corporate security policies. In addition, it restricts lateral movement inside the network to limit the damage from cyber-attacks. It also monitors activity and provides more visibility to help businesses strengthen their IT infrastructure and enhance their security controls.
The most common use case for network access control involves protecting the endpoints of a business. These include laptops, cell phones, printers, closed-circuit television cameras, and automation-heavy devices like light and motion sensors. These devices are often unaccounted for and vulnerable to hacking. But NAC tools ensure they have the proper updates, are free of malware and viruses, and meet other security requirements before connecting to a company’s networks.
NAC solutions are available for wired and wireless networks (WLANs). Most network access control systems offer multi-factor authentication, self-registration, and segmentation features to support specific use cases. For example, BYOD and IoT deployments require a solution with a robust captive portal, guest management, device profiling, and posture assessment capabilities. These capabilities must align with regular traffic to avoid compromising network performance. They must be able to analyze the risk position of every user and device in real-time, regardless of location or data transport type.
Policy Enforcement
Network access control allows network resources to be accessed only by devices and users that follow the organization’s security policies. This helps prevent malware threats and reduce cyber attacks by identifying, isolating, and correcting non-compliant machines without administrator intervention.
It also prevents lateral movement within the network, which can be used to spread malicious files from one device to another. It is often implemented in conjunction with a firewall to provide robust protection.
As part of the policy enforcement process, the NAC solution will evaluate a device or user’s status and determine whether they should be allowed to continue to the next part of the network. This can be done either via a pre-admission or post-admission control.
In addition to the traditional PCs and servers, this technology enables you to apply access controls to various endpoint devices, including laptops, tablets, and mobile phones. This can be particularly useful in addressing your organization’s increased number of BYOD devices.
The NAC solutions that are available on the market today support both out-of-band and in-band deployments. They are typically managed by policy server systems that run on top of existing network infrastructure devices such as switches, routers, and wireless access points. These policy servers are responsible for specifying the usage policies, activating and deactivating them, and providing a user-friendly interface for administration.
Authentication
Network access control uses authentication to determine whether a user or device can enter a network. This is done by comparing the device’s or user’s credentials to those on file in the system. Authentication typically refers to verifying identity, and it’s common for the process to involve passwords or biometric data. The authentication phase is essential because it protects networks against unauthorized entry.
Once an authenticated user is inside the network, NAC monitors the behavior of that user or device. This allows for more granular security, such as restricting data from some network regions to specific users or devices. It also helps prevent lateral movement that could amplify a cyber attack.
NAC solutions can also help protect against malware and other threats by denying access from endpoints that don’t comply with policies. This is an essential feature for many companies, especially those that allow employees to use their devices for work. Without NAC, a malicious file may be able to enter the corporate network through an unsecured USB or wireless connection. But NAC can ensure that all employee devices used for business purposes meet internal security requirements, and they can only access the data corresponding to their privileges within the network. NAC can also quarantine non-compliant devices to keep them from spreading across the enterprise.
