What Are the Best Practices for Network Access Control?

Network administrators can safeguard networking devices with secure configurations, whether through physical or virtual separation. This prevents adversaries from accessing sensitive data or systems and aids incident response.

Many NAC solutions offer pre-admission control, which verifies that a device meets security policies before allowing it to connect to the network. This reduces the surface area for attack and increases agility, scalability, and flexibility.

Authentication

Authentication is the first step in network access control. It requires all devices and users on your network to verify their identity through a series of security checks before they can use resources. This reduces the risk of unauthorized access and data breaches by ensuring that only compliant devices can enter your digital ecosystem.

For example, when you sign in to your Gmail or Facebook account, the service provider presents a login screen and compares the data you entered with the information stored internally. This proves that you are the owner of those login credentials and, thus, authorized to access your account.

This verification process can also occur on a device level with solutions like single sign-on (SSO), which allows you to authenticate once and pass this authentication to all apps requiring it. This eliminates the need for a user to remember multiple randomized passwords and thus reduces the risk of them being compromised by hackers or lost due to human error.

Choosing a network access control solution with robust support for your business needs is essential. For example, if your company has a significant bring-your-own-device (BYOD) or IoT footprint and wants to ensure guest device compliance, look for a solution with solid support for captive portals, auto-registration, and segmentation capabilities. You also want to select a solution that integrates with your zero-trust identity and access management (IAM) policies and unified endpoint security tools to provide cohesive visibility.

Access Control Lists

Network access control is essential to keep your organization running smoothly and reduce security threats. Different types of network access control help ensure that the right people get the right resources at the right time and that unauthorized users can’t access sensitive data.

NAC verifies the identity of users and devices before granting them network access by using authentication protocols, including username/password credentials and digital certificates. It also provides access policies that determine the level of network resources a user or device can access.

It’s essential to maintain a well-documented set of ACL rules. This includes when the rule was added, who, why, and what it is supposed to do. Documenting this information will help prevent unnecessary work and stress for the IT team later.

There are two main categories of ACLs: standard and extended. Every day, ACLs filter traffic based on the source IP address and only allow or block traffic from the source. Unlike standard ACLs, extended ACLs can filter traffic based on source and destination IP addresses and provide different priorities for various types of network traffic. This allows the router to prioritize incoming traffic based on its Type of Service (ToS), Internet Protocol (IP) precedence, and Differentiated Services Code Point (DSCP) priority. The MAC ACL is a variant of the standard ACL and filters traffic by Ethernet MAC address.

Role-Based Access Control

Using roles, admins can grant and manage permissions for large groups of users at once. Roles are created based on the least privilege principle, in which a user gets access to specific locations and resources only on a need-to-know basis. For example, supervisors may need to see employee performance evaluations for their direct reports, but other employees would not.

Rather than managing every user’s devices and apps, a role-based approach can simplify access management for many companies. However, this can be a complicated process to implement. Starting with an iterative, collaborative process is essential so security rules stay relaxed and encourage productivity.

Once roles are in place, admins can enforce policies for all users and devices connecting to the network. Network registration policies can help ensure that all devices are approved and authenticated before they can access company data or applications. Enforcing these policies can help prevent data breaches by keeping malicious software off endpoints. NAC also allows organizations to enact device quarantine policies, which limit access for guest workers and contractors so that they don’t have a chance to infect other devices on the network. If a breach occurs, enforcing quarantine policies can also contain the breach to one isolated network segment, reducing the impact on business operations.

Automation

Network access control solutions vary in how flexible they are for different use cases. For example, some may support many BYOD and IoT scenarios. Others might offer strong support for guest access via captive portals and self-registration, while others might have robust device profiling and posture capabilities.

Clear policy definitions are the most crucial element of any network access control strategy. These policies should spell out who can and cannot access the network, how devices will be authenticated and verified, and under what circumstances access is granted. Some NAC systems can also automatically fix non-compliant devices to prevent malware-infected or rogue devices from joining the network and spreading infections to other machines.

Security administrators can manage NAC policies through a security dashboard hosted on-premise or in the cloud. The dashboard enables device visibility, allows for security policy configurations, maps trends or analytics, and displays security alerts.

Most NAC solutions have an out-of-band component that resides outside the normal flow of network traffic, communicating with infrastructure devices that make access decisions in the background. Some network access control systems integrate that decision-making into traffic flow for more efficient enforcement. Other options, such as zero-trust networking (or “never” trust, always verify”), move away from perimeter-based security by requiring credentials for both users and devices before allowing access to the network.