- A
To establish a reliable connection between two hosts
Correct. The three-way handshake sets up a TCP connection with synchronized sequence numbers.
- B
To terminate a connection gracefully
Why wrong: Termination uses a four-way handshake (FIN-ACK), not three-way.
- C
To resolve an IP address to a MAC address
Why wrong: ARP performs IP-to-MAC resolution, not TCP.
- D
To encrypt data between two devices
Why wrong: Encryption is provided by protocols like TLS, not the TCP handshake.
Question 146 of 520
TCP Three-Way Handshake: How a Reliable Connection is Established
This N10-009 practice question tests your understanding of networking concepts. Compare every option against the stated constraints before choosing — the best answer satisfies all requirements, not just the most obvious one. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which of the following best describes the purpose of the TCP three-way handshake?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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
Correct. The three-way handshake sets up a TCP connection with synchronized sequence numbers.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
To terminate a connection gracefully
Why it's wrong here
Termination uses a four-way handshake (FIN-ACK), not three-way.
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
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
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
Correct. The three-way handshake sets up a TCP connection with synchronized sequence numbers.
✗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?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates 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.
Detailed technical explanation
How to think about this question
During the three-way handshake, the client sends a SYN segment with a randomly generated initial sequence number (ISN), the server responds with a SYN-ACK that acknowledges the client's ISN plus one and provides its own ISN, and the client sends an ACK acknowledging the server's ISN plus one. This sequence number synchronization is critical for reliable data delivery, as it allows both hosts to track which bytes have been received and to detect lost or out-of-order segments.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the N10-009 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Visual reference
What to study next
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FAQ
Questions learners often ask
What does this N10-009 question test?
Networking Concepts — This question tests Networking Concepts — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: 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.
What should I do if I get this N10-009 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more ways 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.
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Last reviewed: Jun 11, 2026
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.
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