N10-009 Networking Concepts Practice Question
Which of the following best describes the purpose of the TCP three-way handshake?
⚠ Common exam trap
Many exam-takers confuse the TCP three-way handshake with connection termination (the four-way handshake) or with lower-layer address resolution protocols like ARP, leading them to select the graceful termination or IP-to-MAC resolution options.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
To establish a reliable connection between two hosts
The TCP three-way handshake is the process by which two hosts synchronize sequence numbers and establish a reliable connection before data transfer begins. It involves the exchange of SYN, SYN-ACK, and ACK segments, ensuring both sides are ready to communicate and agree on initial sequence numbers (ISNs) as defined in RFC 793.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
To establish a reliable connection between two hosts
Why this is correct
The TCP three-way handshake is fundamental for initiating a reliable, full-duplex connection between a client and a server. It involves the exchange of SYN, SYN-ACK, and ACK packets to synchronize initial sequence numbers, ensuring that both hosts agree on where data transmission will begin. This process reserves resources and establishes the necessary state for ordered and error-checked data transfer across the network.
- ✗
To terminate a connection gracefully
Why it's wrong here
Graceful connection termination in TCP is achieved through a four-way handshake, involving the exchange of FIN and ACK segments from both sides to signal the end of data transmission. This distinct process allows each host to independently close its sending half of the connection, ensuring all pending data is delivered before the connection is fully dismantled, which is different from the initial connection setup.
When this WOULD be correct
In a question asking 'Which process uses FIN flags to close a TCP session?', option B would be correct, as graceful termination involves exchanging FIN and ACK packets.
- ✗
To resolve an IP address to a MAC address
Why it's wrong here
Resolving an IP address to a corresponding MAC address is the primary function of the Address Resolution Protocol (ARP), which operates at the Data Link Layer (Layer 2) and Network Layer (Layer 3). The TCP three-way handshake, conversely, operates at the Transport Layer (Layer 4) and is solely concerned with establishing logical, end-to-end connections for application data, not physical address mapping.
When this WOULD be correct
This option would be correct in a question asking: 'Which protocol is used to resolve an IP address to a MAC address in a local network?'
- ✗
To encrypt data between two devices
Why it's wrong here
Encrypting data between two devices is the responsibility of higher-layer protocols, such as Transport Layer Security (TLS) or Secure Sockets Layer (SSL), which operate above TCP in the application layer stack. The TCP three-way handshake's sole purpose is to establish a reliable data stream, providing no inherent mechanisms for data confidentiality or integrity protection.
When this WOULD be correct
This option would be correct for a question like: 'Which of the following best describes the purpose of TLS?' or 'Which protocol provides encryption between two devices?'
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓To establish a reliable connection between two hostsCorrect answer▾
Why this is correct
The TCP three-way handshake is fundamental for initiating a reliable, full-duplex connection between a client and a server. It involves the exchange of SYN, SYN-ACK, and ACK packets to synchronize initial sequence numbers, ensuring that both hosts agree on where data transmission will begin. This process reserves resources and establishes the necessary state for ordered and error-checked data transfer across the network.
✗To terminate a connection gracefullyWrong answer — click to see why▾
Why this is wrong here
The TCP three-way handshake is used to establish a connection, not to terminate one. Termination uses a four-way handshake with FIN flags.
★ When this WOULD be the correct answer
In a question asking 'Which process uses FIN flags to close a TCP session?', option B would be correct, as graceful termination involves exchanging FIN and ACK packets.
Why candidates choose this
Candidates may confuse the handshake process for termination because both involve multiple packet exchanges, or they may think 'handshake' applies to both establishment and termination.
✗To resolve an IP address to a MAC addressWrong answer — click to see why▾
Why this is wrong here
The TCP three-way handshake is used to establish a connection, not to resolve IP addresses to MAC addresses; that is the function of ARP (Address Resolution Protocol).
★ When this WOULD be the correct answer
This option would be correct in a question asking: 'Which protocol is used to resolve an IP address to a MAC address in a local network?'
Why candidates choose this
Candidates may confuse the handshake's role in network communication with address resolution, or they might think the handshake involves address mapping because it occurs at the start of a session.
✗To encrypt data between two devicesWrong answer — click to see why▾
Why this is wrong here
The TCP three-way handshake is used to establish a connection, not to encrypt data. Encryption is handled by protocols like TLS or IPsec, not by TCP itself.
★ When this WOULD be the correct answer
This option would be correct for a question like: 'Which of the following best describes the purpose of TLS?' or 'Which protocol provides encryption between two devices?'
Why candidates choose this
Candidates may confuse TCP with secure protocols that also involve handshakes (e.g., TLS handshake), or mistakenly think TCP provides security features like encryption.
Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
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Key term
TCP
TCP (Transmission Control Protocol) is a core internet protocol that ensures data is sent reliably and in order between devices over a network.
Key term
TCP
TCP is a connection-oriented transport layer protocol that ensures reliable, ordered, and error-checked delivery of data between applications over IP networks.
About these practice questions
One of 464 original N10-009 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on N10-009
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A network technician is explaining the difference between TCP and UDP to a junior technician. Which of the following correctly identifies a characteristic of TCP but NOT of UDP?
medium- A.It provides connectionless communication with minimal overhead.
- B.It supports multicast and broadcast transmissions.
- ✓ C.It uses a three-way handshake to establish a connection before data transfer.
- D.It is commonly used for real-time applications like VoIP and video streaming.
Why C: TCP is a connection-oriented protocol that uses a three-way handshake (SYN, SYN-ACK, ACK) to establish a reliable connection before any data is transmitted, ensuring ordered delivery and error recovery. UDP, in contrast, is connectionless and sends datagrams without any prior setup, making the three-way handshake a defining characteristic of TCP only.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This N10-009 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the N10-009 exam.