What is switch port security?

• A. Binding allowed MAC addresses to a switch port to prevent unauthorized devices from connecting.
• B. Setting firewall rules on a switch to block external IPs.
• C. Encrypting traffic between devices on the same switch port.
• D. Disabling all ports on a switch except one.

Answer: (A)

Switch port security is a Layer 2 access-control feature that binds specific MAC addresses to a switch port, so only devices with those addresses can send frames through that port. This is why the best answer describes binding allowed MAC addresses to a port to prevent unauthorized devices from connecting. It lets you specify which devices are permitted on that edge port, and you can enable mechanisms like sticky learning to automatically learn and persist addresses in the switch configuration. If a device with a different MAC address tries to use the port, the switch can block traffic, log the event, or even shut the port down depending on how you configure it. This protects against rogue devices and MAC spoofing on access ports.

The other options don’t fit because switch port security focuses on controlling which devices can access a port by their MAC address, not on firewall-like IP filtering, encryption of traffic on the same port, or disabling multiple ports.