Which access control component, implementation, or protocol restricts LAN access through publicly accessible switch ports?

The access control component that restricts LAN access through publicly accessible switch ports is 802.1X. Here’s how it fits into this context:

1. 802.1X: This is an IEEE standard for port-based Network Access Control (PNAC). It is used to provide authentication to devices trying to connect to a LAN or WLAN. 802.1X restricts access to the network through publicly accessible switch ports until the device is authenticated. It’s a key protocol used in securing wired and wireless networks by preventing unauthorized network access at the port level.
2. Accounting: This component involves tracking and recording user activities on the network, mainly for auditing and billing purposes. It does not restrict access to network resources.
3. Authorization: While authorization determines what an authenticated user is allowed to do on the network (like accessing certain resources or services), it doesn’t directly restrict access through physical switch ports.
4. Authentication: This process verifies the identity of a user or device. While it’s a crucial step before granting access to the network, it doesn’t specifically address the control of access through switch ports.

In summary, 802.1X is specifically designed to control access to a LAN through publicly accessible switch ports, making it the correct answer.