Cisco NetAcad CCNA 1 – Chapter 4
Exam Practice: Network Protocols,
TCP/IP & OSI Model | 50+ Questions
with Answers & Rationales
(2025/2026)”
Which three layers of the OSI model map to the application layer of
the TCP/IP model?
A. Physical, Data Link, Network
B. Application, Presentation, Session
C. Transport, Network, Data Link
D. Session, Transport, Physical
<<,answer<<<: B
Rationale: The TCP/IP application layer includes OSI Application,
Presentation, and Session layers.
Q2.
What is the correct order of PDU (Protocol Data Unit) names from
the top to bottom of the OSI model?
A. Frame → Packet → Segment → Bits
B. Segment → Packet → Frame → Bits
,C. Bits → Frame → Packet → Segment
D. Segment → Frame → Packet → Bits
<<,answer<<<: B
Rationale: Transport = Segment, Network = Packet, Data Link =
Frame, Physical = Bits.
Q3.
Which protocol provides connection-oriented, reliable delivery?
A. UDP
B. IP
C. TCP
D. ICMP
<<,answer<<<: C
Rationale: TCP provides reliable, connection-oriented delivery with
acknowledgments.
Q4.
Which application protocol uses port 53?
A. FTP
B. DNS
C. HTTP
D. DHCP
<<,answer<<<: B
Rationale: DNS uses port 53 (UDP and sometimes TCP).
,Q5.
Which two protocols are used for file transfers? (Choose 2)
A. FTP
B. SMTP
C. TFTP
D. SNMP
<<,answer<<<: A, C
Rationale: FTP (reliable, TCP-based) and TFTP (simpler, UDP-
based).
Q6.
Which statement describes UDP correctly?
A. Connection-oriented, reliable, slow
B. Connectionless, fast, best-effort delivery
C. Used only by TCP
D. Provides sequencing and acknowledgments
<<,answer<<<: B
Rationale: UDP is lightweight, connectionless, and does not
guarantee delivery.
Q7.
A web client requests a web page. Which transport layer protocol is
used?
A. UDP
B. TCP
, C. ICMP
D. ARP
<<,answer<<<: B
Rationale: HTTP uses TCP (port 80/443).
Q8.
Which protocol provides dynamic addressing for hosts?
A. DNS
B. DHCP
C. ARP
D. FTP
<<,answer<<<: B
Rationale: DHCP automatically assigns IP addresses and other
configuration details.
Q9.
What is the primary function of DNS?
A. Assign IP addresses
B. Resolve domain names to IP addresses
C. Transfer files
D. Encrypt traffic
<<,answer<<<: B
Rationale: DNS translates human-readable names into machine IP
addresses.
Exam Practice: Network Protocols,
TCP/IP & OSI Model | 50+ Questions
with Answers & Rationales
(2025/2026)”
Which three layers of the OSI model map to the application layer of
the TCP/IP model?
A. Physical, Data Link, Network
B. Application, Presentation, Session
C. Transport, Network, Data Link
D. Session, Transport, Physical
<<,answer<<<: B
Rationale: The TCP/IP application layer includes OSI Application,
Presentation, and Session layers.
Q2.
What is the correct order of PDU (Protocol Data Unit) names from
the top to bottom of the OSI model?
A. Frame → Packet → Segment → Bits
B. Segment → Packet → Frame → Bits
,C. Bits → Frame → Packet → Segment
D. Segment → Frame → Packet → Bits
<<,answer<<<: B
Rationale: Transport = Segment, Network = Packet, Data Link =
Frame, Physical = Bits.
Q3.
Which protocol provides connection-oriented, reliable delivery?
A. UDP
B. IP
C. TCP
D. ICMP
<<,answer<<<: C
Rationale: TCP provides reliable, connection-oriented delivery with
acknowledgments.
Q4.
Which application protocol uses port 53?
A. FTP
B. DNS
C. HTTP
D. DHCP
<<,answer<<<: B
Rationale: DNS uses port 53 (UDP and sometimes TCP).
,Q5.
Which two protocols are used for file transfers? (Choose 2)
A. FTP
B. SMTP
C. TFTP
D. SNMP
<<,answer<<<: A, C
Rationale: FTP (reliable, TCP-based) and TFTP (simpler, UDP-
based).
Q6.
Which statement describes UDP correctly?
A. Connection-oriented, reliable, slow
B. Connectionless, fast, best-effort delivery
C. Used only by TCP
D. Provides sequencing and acknowledgments
<<,answer<<<: B
Rationale: UDP is lightweight, connectionless, and does not
guarantee delivery.
Q7.
A web client requests a web page. Which transport layer protocol is
used?
A. UDP
B. TCP
, C. ICMP
D. ARP
<<,answer<<<: B
Rationale: HTTP uses TCP (port 80/443).
Q8.
Which protocol provides dynamic addressing for hosts?
A. DNS
B. DHCP
C. ARP
D. FTP
<<,answer<<<: B
Rationale: DHCP automatically assigns IP addresses and other
configuration details.
Q9.
What is the primary function of DNS?
A. Assign IP addresses
B. Resolve domain names to IP addresses
C. Transfer files
D. Encrypt traffic
<<,answer<<<: B
Rationale: DNS translates human-readable names into machine IP
addresses.
