CCNA: Cisco Certified Network Associate — Question 1

How do TCP and UDP differ in the way that they establish a connection between two endpoints?

Answer options

• A. TCP uses the three-way handshake, and UDP does not guarantee message delivery.
• B. TCP uses synchronization packets, and UDP uses acknowledgment packets.
• C. UDP provides reliable message transfer, and TCP is a connectionless protocol.
• D. UDP uses SYN, SYN ACK, and FIN bits in the frame header while TCP uses SYN, SYN ACK, and ACK bits.

Correct answer: A

Explanation

The correct answer is A because TCP establishes a connection using a three-way handshake process, which ensures reliable communication, while UDP does not have such a mechanism and does not guarantee message delivery. Options B and D are incorrect as they misrepresent the role of packets in both protocols, and option C inaccurately describes UDP as providing reliable message transfer, which is not the case.