A network administrator wants to ensure that users do not connect any unauthorized devices to the company network. Each desk needs to connect a VoIP phone and computer. Which of the following is the…

Enforcing authentication for network devices, often achieved through 802.1X Network Access Control (NAC), validates the identity of any device attempting to connect to a network port. This mechanism ensures that only authorized devices, such as the specified VoIP phones and computers with valid credentials or certificates, are granted network access, thereby preventing unauthorized hardware from connecting.

While configuring devices on separate VLANs logically segments network traffic and enhances security, it does not inherently prevent an unauthorized device from physically connecting to an access port and gaining entry to one of those VLANs if no port-level authentication is enforced.

Port channels, also known as link aggregation, are used to combine multiple physical network links into a single logical link to increase bandwidth and provide redundancy, which is unrelated to preventing unauthorized device connections.

Making users sign an Acceptable Use Agreement (AUA) is a policy-based control that defines appropriate network behavior and acts as a deterrent, but it does not technically prevent an unauthorized device from physically connecting to and accessing the network.