CS6250 COMPUTER NETWORK EXAM 1 PRACTICE EXAM – QUESTIONS AND
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES |
DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
Core Domains
Network Architecture and Layering (OSI and TCP/IP Models)
Application Layer Protocols (HTTP, DNS, SMTP, FTP)
Transport Layer Services (TCP, UDP, Flow Control, Congestion Control)
Network Layer Functions (IP Addressing, Subnetting, Routing Algorithms)
Link Layer and Local Area Networks (Ethernet, ARP, Switching, VLANs)
Wireless and Mobile Networking (802.11, Cellular, Mobility Management)
Network Security (Cryptography, TLS, Firewalls, IPSec)
Network Management, Operations, and Troubleshooting
Software-Defined Networking and Network Virtualization
Ethics, Regulatory Compliance, and Professional Standards in Networking
Introduction
This examination assesses a candidate's comprehensive knowledge of computer
networking principles, protocols, and practices. It is designed to evaluate the skills
required to design, implement, manage, and secure modern network infrastructures.
The assessment employs both multiple-choice and scenario-based questions to test
foundational theory and its application in real-world contexts. A significant emphasis
is placed on critical thinking, decision-making, and understanding the ethical and
regulatory landscape that governs professional networking. Successful completion
demonstrates readiness to address complex challenges in the field.
SECTION ONE: QUESTIONS 1–50
,Question 1
Which layer of the OSI model is responsible for translating data formats and
ensuring that data sent from one system's application layer is readable by another
system's application layer?
A. Transport Layer
B. Session Layer
C. Presentation Layer
D. Application Layer
🟢 Correct Answer: C. Presentation Layer
🔴 Explanation: The Presentation Layer (Layer 6) of the OSI model handles data
translation, encryption, and compression, ensuring that data from the application
layer of one system is readable by the application layer of another.
Question 2
A network administrator is troubleshooting a connectivity issue and uses the ping
command. Which protocol is being primarily utilized by this command to test
reachability?
A. TCP
B. UDP
C. ICMP
D. ARP
🟢 Correct Answer: C. ICMP
🔴 Explanation: The ping command uses the Internet Control Message Protocol
(ICMP) to send Echo Request messages and receive Echo Reply messages, which
tests the reachability of a host on an IP network.
Question 3
,What is the primary function of the Domain Name System (DNS)?
A. To assign dynamic IP addresses to hosts on a network.
B. To encrypt traffic between a web server and a client.
C. To translate human-readable domain names into IP addresses.
D. To route packets between different autonomous systems.
🟢 Correct Answer: C. To translate human-readable domain names into IP
addresses.
🔴 Explanation: DNS is a hierarchical and decentralized naming system for
computers, services, or other resources connected to the Internet or a private
network. Its most prominent function is to translate domain names (e.g.,
www.example.com) into the numerical IP addresses needed for locating and
identifying computer services and devices.
Question 4
In a TCP three-way handshake, what is the correct sequence of flags exchanged
between a client and a server to establish a connection?
A. SYN, ACK, SYN-ACK
B. SYN, SYN-ACK, ACK
C. ACK, SYN, ACK
D. SYN-ACK, SYN, ACK
🟢 Correct Answer: B. SYN, SYN-ACK, ACK
🔴 Explanation: The TCP three-way handshake begins with the client sending a
SYN (synchronize) packet. The server responds with a SYN-ACK (synchronize-
acknowledge) packet. Finally, the client sends an ACK (acknowledge) packet to
complete the connection establishment.
Question 5
, Which of the following is a connectionless transport layer protocol that provides a
"best-effort" delivery service?
A. TCP
B. UDP
C. SCTP
D. DCCP
🟢 Correct Answer: B. UDP
🔴 Explanation: The User Datagram Protocol (UDP) is a connectionless protocol. It
does not establish a connection before sending data, provides no guarantee of
delivery, ordering, or duplicate protection, making it a "best-effort" service.
Question 6
A company is assigned the IP address block 192.168.10.0/24. The network
administrator needs to create 8 subnets. What subnet mask should be used?
A. 255.255.255.128
B. 255.255.255.192
C. 255.255.255.224
D. 255.255.255.240
🟢 Correct Answer: C. 255.255.255.224
🔴 Explanation: To create 8 subnets, 3 bits must be borrowed from the host
portion (2^3 = 8). The original subnet mask is /24 (255.255.255.0). Adding 3 bits
gives a new prefix of /27, which corresponds to the subnet mask 255.255.255.224.
Question 7
What is the primary purpose of the Address Resolution Protocol (ARP)?
A. To map a known IP address to a MAC address.
B. To map a known MAC address to an IP address.
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES |
DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
Core Domains
Network Architecture and Layering (OSI and TCP/IP Models)
Application Layer Protocols (HTTP, DNS, SMTP, FTP)
Transport Layer Services (TCP, UDP, Flow Control, Congestion Control)
Network Layer Functions (IP Addressing, Subnetting, Routing Algorithms)
Link Layer and Local Area Networks (Ethernet, ARP, Switching, VLANs)
Wireless and Mobile Networking (802.11, Cellular, Mobility Management)
Network Security (Cryptography, TLS, Firewalls, IPSec)
Network Management, Operations, and Troubleshooting
Software-Defined Networking and Network Virtualization
Ethics, Regulatory Compliance, and Professional Standards in Networking
Introduction
This examination assesses a candidate's comprehensive knowledge of computer
networking principles, protocols, and practices. It is designed to evaluate the skills
required to design, implement, manage, and secure modern network infrastructures.
The assessment employs both multiple-choice and scenario-based questions to test
foundational theory and its application in real-world contexts. A significant emphasis
is placed on critical thinking, decision-making, and understanding the ethical and
regulatory landscape that governs professional networking. Successful completion
demonstrates readiness to address complex challenges in the field.
SECTION ONE: QUESTIONS 1–50
,Question 1
Which layer of the OSI model is responsible for translating data formats and
ensuring that data sent from one system's application layer is readable by another
system's application layer?
A. Transport Layer
B. Session Layer
C. Presentation Layer
D. Application Layer
🟢 Correct Answer: C. Presentation Layer
🔴 Explanation: The Presentation Layer (Layer 6) of the OSI model handles data
translation, encryption, and compression, ensuring that data from the application
layer of one system is readable by the application layer of another.
Question 2
A network administrator is troubleshooting a connectivity issue and uses the ping
command. Which protocol is being primarily utilized by this command to test
reachability?
A. TCP
B. UDP
C. ICMP
D. ARP
🟢 Correct Answer: C. ICMP
🔴 Explanation: The ping command uses the Internet Control Message Protocol
(ICMP) to send Echo Request messages and receive Echo Reply messages, which
tests the reachability of a host on an IP network.
Question 3
,What is the primary function of the Domain Name System (DNS)?
A. To assign dynamic IP addresses to hosts on a network.
B. To encrypt traffic between a web server and a client.
C. To translate human-readable domain names into IP addresses.
D. To route packets between different autonomous systems.
🟢 Correct Answer: C. To translate human-readable domain names into IP
addresses.
🔴 Explanation: DNS is a hierarchical and decentralized naming system for
computers, services, or other resources connected to the Internet or a private
network. Its most prominent function is to translate domain names (e.g.,
www.example.com) into the numerical IP addresses needed for locating and
identifying computer services and devices.
Question 4
In a TCP three-way handshake, what is the correct sequence of flags exchanged
between a client and a server to establish a connection?
A. SYN, ACK, SYN-ACK
B. SYN, SYN-ACK, ACK
C. ACK, SYN, ACK
D. SYN-ACK, SYN, ACK
🟢 Correct Answer: B. SYN, SYN-ACK, ACK
🔴 Explanation: The TCP three-way handshake begins with the client sending a
SYN (synchronize) packet. The server responds with a SYN-ACK (synchronize-
acknowledge) packet. Finally, the client sends an ACK (acknowledge) packet to
complete the connection establishment.
Question 5
, Which of the following is a connectionless transport layer protocol that provides a
"best-effort" delivery service?
A. TCP
B. UDP
C. SCTP
D. DCCP
🟢 Correct Answer: B. UDP
🔴 Explanation: The User Datagram Protocol (UDP) is a connectionless protocol. It
does not establish a connection before sending data, provides no guarantee of
delivery, ordering, or duplicate protection, making it a "best-effort" service.
Question 6
A company is assigned the IP address block 192.168.10.0/24. The network
administrator needs to create 8 subnets. What subnet mask should be used?
A. 255.255.255.128
B. 255.255.255.192
C. 255.255.255.224
D. 255.255.255.240
🟢 Correct Answer: C. 255.255.255.224
🔴 Explanation: To create 8 subnets, 3 bits must be borrowed from the host
portion (2^3 = 8). The original subnet mask is /24 (255.255.255.0). Adding 3 bits
gives a new prefix of /27, which corresponds to the subnet mask 255.255.255.224.
Question 7
What is the primary purpose of the Address Resolution Protocol (ARP)?
A. To map a known IP address to a MAC address.
B. To map a known MAC address to an IP address.
