CCNA: Cisco Certified Network Associate — Question 323

What is a network appliance that checks the state of a packet to determine whether the packet is legitimate?

Answer options

• A. Layer 2 switch
• B. LAN controller
• C. load balancer
• D. firewall

Correct answer: D

Explanation

The correct answer is D, firewall, as it is specifically designed to inspect packets and enforce security policies. A Layer 2 switch (A) operates at the data link layer and does not analyze packet contents for legitimacy. A LAN controller (B) manages local area network traffic but does not inspect packet legitimacy. A load balancer (C) distributes network or application traffic but does not verify packet states.