IT2 STUDY ADVANCEMENT EXAM - U.S. Navy |
2026/2027 Questions with 100% Correct Answers |
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DOMAIN 1: TELECOMMUNICATIONS FUNDAMENTALS & SYSTEMS (90 Questions)
Sub-Topic 1.1: OSI Model Layers and Functions (15 Questions)
Question 1 (Multiple-Choice)
Which OSI layer is responsible for encryption, compression, and data formatting such as ASCII, JPEG,
and MPEG?
A) Layer 5 - Session
B) Layer 6 - Presentation
C) Layer 7 - Application
D) Layer 4 - Transport
Answer: B) Layer 6 - Presentation [CORRECT]
Rationale: Layer 6 (Presentation) handles data translation, encryption/decryption, and compression. It
ensures that data sent from one system's application layer can be read by another system's
application layer. In Navy shipboard networks, this layer handles the encryption of classified traffic
before transmission over unsecured media.
Question 2 (Multiple-Choice)
A Sailor aboard USS CARL VINSON is troubleshooting a network issue where data frames are not
reaching the correct VLAN. At which OSI layer does this problem most likely originate?
A) Layer 1 - Physical
B) Layer 3 - Network
C) Layer 2 - Data Link
D) Layer 4 - Transport
Answer: C) Layer 2 - Data Link [CORRECT]
Rationale: VLANs (Virtual Local Area Networks) operate at Layer 2 (Data Link layer) using MAC
addresses and 802.1Q tagging. Frame switching, ARP, and VLAN trunking are all Layer 2 functions. In
Navy shipboard networks, improper VLAN configuration on switches can cause frames to be
forwarded to incorrect network segments.
Question 3 (Multiple-Choice)
,Which protocol operates at Layer 4 (Transport) of the OSI model and provides connection-oriented,
reliable delivery with sequencing and acknowledgment?
A) UDP
B) IP
C) TCP
D) ICMP
Answer: C) TCP [CORRECT]
Rationale: TCP (Transmission Control Protocol) is connection-oriented, providing reliable delivery
through three-way handshakes (SYN, SYN-ACK, ACK), sequence numbers, and acknowledgments. UDP
is connectionless and unreliable. TCP is critical for Navy message traffic and file transfers where data
integrity is paramount.
Question 4 (Multiple-Choice)
During a shore installation network outage, a technician discovers that a fiber optic cable has been
severed. This failure affects which OSI layer?
A) Layer 2 - Data Link
B) Layer 1 - Physical
C) Layer 3 - Network
D) Layer 7 - Application
Answer: B) Layer 1 - Physical [CORRECT]
Rationale: Layer 1 (Physical) encompasses all physical media including cables, fiber optics, radio
frequency, hubs, and repeaters. A severed cable is a physical layer failure. In Navy
telecommunications, Physical layer troubleshooting includes checking fiber continuity, RF signal
strength, and cable integrity using OTDRs (Optical Time-Domain Reflectometers).
Question 5 (Multiple-Choice)
Which OSI layer device uses MAC addresses to forward frames within the same network segment?
A) Router
B) Hub
C) Switch
D) Firewall
Answer: C) Switch [CORRECT]
Rationale: Switches operate at Layer 2 (Data Link) and use MAC address tables to forward frames to
specific ports. Routers use IP addresses (Layer 3), hubs are Layer 1 devices that broadcast to all ports,
,and firewalls typically operate at Layers 3-7. Navy shipboard networks rely on Layer 2 switches for
internal network segmentation.
Question 6 (Multiple-Choice)
NetBIOS and RPC are examples of protocols that operate at which OSI layer?
A) Layer 4 - Transport
B) Layer 5 - Session
C) Layer 6 - Presentation
D) Layer 7 - Application
Answer: B) Layer 5 - Session [CORRECT]
Rationale: Layer 5 (Session) establishes, manages, and terminates connections between applications.
NetBIOS (Network Basic Input/Output System) and RPC (Remote Procedure Call) manage session
establishment and termination. In Navy network administration, session layer issues can cause
authentication failures between shipboard workstations and shore-based servers.
Question 7 (Multiple-Choice)
DNS, HTTP, FTP, and Telnet are protocols associated with which OSI layer?
A) Layer 5 - Session
B) Layer 6 - Presentation
C) Layer 7 - Application
D) Layer 4 - Transport
Answer: C) Layer 7 - Application [CORRECT]
Rationale: Layer 7 (Application) provides the interface between end-user applications and network
services. DNS resolves hostnames to IP addresses, HTTP enables web browsing, FTP transfers files, and
Telnet provides remote terminal access. Navy ITs must understand these protocols for
troubleshooting NMCI and ONE-Net connectivity issues.
Question 8 (Multiple-Choice)
Which device operates at Layer 3 (Network) and uses IP addresses to determine the best path for
packet forwarding?
A) Switch
B) Bridge
C) Router
D) Repeater
Answer: C) Router [CORRECT]
, Rationale: Routers operate at Layer 3 (Network) and use IP addresses and routing tables to forward
packets between different networks. They make path determination decisions based on routing
protocols (RIP, OSPF, EIGRP, BGP). In Navy networks, routers connect shipboard LANs to shore-based
networks via SATCOM links.
Question 9 (Multiple-Choice)
ARP (Address Resolution Protocol) operates at which OSI layer to map IP addresses to MAC
addresses?
A) Layer 1 - Physical
B) Layer 2 - Data Link
C) Layer 3 - Network
D) Layer 4 - Transport
Answer: B) Layer 2 - Data Link [CORRECT]
Rationale: ARP operates at Layer 2 (Data Link) with assistance from Layer 3. It resolves IP addresses
(Layer 3) to MAC addresses (Layer 2) so that frames can be properly addressed for local network
delivery. ARP cache poisoning is a common Layer 2 attack vector that Navy ITs must defend against.
Question 10 (Multiple-Choice)
ICMP (Internet Control Message Protocol) is primarily used for which function?
A) File transfer between systems
B) Error reporting and diagnostic testing
C) Encryption of data in transit
D) Session establishment between hosts
Answer: B) Error reporting and diagnostic testing [CORRECT]
Rationale: ICMP operates at Layer 3 (Network) and is used for error reporting (destination
unreachable, time exceeded) and diagnostics (ping, traceroute). It does not transfer files, encrypt
data, or establish sessions. Navy network administrators use ICMP extensively for connectivity testing
across NMCI and tactical networks.
Question 11 (Multiple-Choice)
A technician is configuring a shipboard network and needs to segment traffic between combat
systems and administrative networks. Which Layer 2 technology should be implemented?
A) NAT at Layer 3
B) VLAN tagging at Layer 2
C) Application proxy at Layer 7
2026/2027 Questions with 100% Correct Answers |
Everything you need!!
DOMAIN 1: TELECOMMUNICATIONS FUNDAMENTALS & SYSTEMS (90 Questions)
Sub-Topic 1.1: OSI Model Layers and Functions (15 Questions)
Question 1 (Multiple-Choice)
Which OSI layer is responsible for encryption, compression, and data formatting such as ASCII, JPEG,
and MPEG?
A) Layer 5 - Session
B) Layer 6 - Presentation
C) Layer 7 - Application
D) Layer 4 - Transport
Answer: B) Layer 6 - Presentation [CORRECT]
Rationale: Layer 6 (Presentation) handles data translation, encryption/decryption, and compression. It
ensures that data sent from one system's application layer can be read by another system's
application layer. In Navy shipboard networks, this layer handles the encryption of classified traffic
before transmission over unsecured media.
Question 2 (Multiple-Choice)
A Sailor aboard USS CARL VINSON is troubleshooting a network issue where data frames are not
reaching the correct VLAN. At which OSI layer does this problem most likely originate?
A) Layer 1 - Physical
B) Layer 3 - Network
C) Layer 2 - Data Link
D) Layer 4 - Transport
Answer: C) Layer 2 - Data Link [CORRECT]
Rationale: VLANs (Virtual Local Area Networks) operate at Layer 2 (Data Link layer) using MAC
addresses and 802.1Q tagging. Frame switching, ARP, and VLAN trunking are all Layer 2 functions. In
Navy shipboard networks, improper VLAN configuration on switches can cause frames to be
forwarded to incorrect network segments.
Question 3 (Multiple-Choice)
,Which protocol operates at Layer 4 (Transport) of the OSI model and provides connection-oriented,
reliable delivery with sequencing and acknowledgment?
A) UDP
B) IP
C) TCP
D) ICMP
Answer: C) TCP [CORRECT]
Rationale: TCP (Transmission Control Protocol) is connection-oriented, providing reliable delivery
through three-way handshakes (SYN, SYN-ACK, ACK), sequence numbers, and acknowledgments. UDP
is connectionless and unreliable. TCP is critical for Navy message traffic and file transfers where data
integrity is paramount.
Question 4 (Multiple-Choice)
During a shore installation network outage, a technician discovers that a fiber optic cable has been
severed. This failure affects which OSI layer?
A) Layer 2 - Data Link
B) Layer 1 - Physical
C) Layer 3 - Network
D) Layer 7 - Application
Answer: B) Layer 1 - Physical [CORRECT]
Rationale: Layer 1 (Physical) encompasses all physical media including cables, fiber optics, radio
frequency, hubs, and repeaters. A severed cable is a physical layer failure. In Navy
telecommunications, Physical layer troubleshooting includes checking fiber continuity, RF signal
strength, and cable integrity using OTDRs (Optical Time-Domain Reflectometers).
Question 5 (Multiple-Choice)
Which OSI layer device uses MAC addresses to forward frames within the same network segment?
A) Router
B) Hub
C) Switch
D) Firewall
Answer: C) Switch [CORRECT]
Rationale: Switches operate at Layer 2 (Data Link) and use MAC address tables to forward frames to
specific ports. Routers use IP addresses (Layer 3), hubs are Layer 1 devices that broadcast to all ports,
,and firewalls typically operate at Layers 3-7. Navy shipboard networks rely on Layer 2 switches for
internal network segmentation.
Question 6 (Multiple-Choice)
NetBIOS and RPC are examples of protocols that operate at which OSI layer?
A) Layer 4 - Transport
B) Layer 5 - Session
C) Layer 6 - Presentation
D) Layer 7 - Application
Answer: B) Layer 5 - Session [CORRECT]
Rationale: Layer 5 (Session) establishes, manages, and terminates connections between applications.
NetBIOS (Network Basic Input/Output System) and RPC (Remote Procedure Call) manage session
establishment and termination. In Navy network administration, session layer issues can cause
authentication failures between shipboard workstations and shore-based servers.
Question 7 (Multiple-Choice)
DNS, HTTP, FTP, and Telnet are protocols associated with which OSI layer?
A) Layer 5 - Session
B) Layer 6 - Presentation
C) Layer 7 - Application
D) Layer 4 - Transport
Answer: C) Layer 7 - Application [CORRECT]
Rationale: Layer 7 (Application) provides the interface between end-user applications and network
services. DNS resolves hostnames to IP addresses, HTTP enables web browsing, FTP transfers files, and
Telnet provides remote terminal access. Navy ITs must understand these protocols for
troubleshooting NMCI and ONE-Net connectivity issues.
Question 8 (Multiple-Choice)
Which device operates at Layer 3 (Network) and uses IP addresses to determine the best path for
packet forwarding?
A) Switch
B) Bridge
C) Router
D) Repeater
Answer: C) Router [CORRECT]
, Rationale: Routers operate at Layer 3 (Network) and use IP addresses and routing tables to forward
packets between different networks. They make path determination decisions based on routing
protocols (RIP, OSPF, EIGRP, BGP). In Navy networks, routers connect shipboard LANs to shore-based
networks via SATCOM links.
Question 9 (Multiple-Choice)
ARP (Address Resolution Protocol) operates at which OSI layer to map IP addresses to MAC
addresses?
A) Layer 1 - Physical
B) Layer 2 - Data Link
C) Layer 3 - Network
D) Layer 4 - Transport
Answer: B) Layer 2 - Data Link [CORRECT]
Rationale: ARP operates at Layer 2 (Data Link) with assistance from Layer 3. It resolves IP addresses
(Layer 3) to MAC addresses (Layer 2) so that frames can be properly addressed for local network
delivery. ARP cache poisoning is a common Layer 2 attack vector that Navy ITs must defend against.
Question 10 (Multiple-Choice)
ICMP (Internet Control Message Protocol) is primarily used for which function?
A) File transfer between systems
B) Error reporting and diagnostic testing
C) Encryption of data in transit
D) Session establishment between hosts
Answer: B) Error reporting and diagnostic testing [CORRECT]
Rationale: ICMP operates at Layer 3 (Network) and is used for error reporting (destination
unreachable, time exceeded) and diagnostics (ping, traceroute). It does not transfer files, encrypt
data, or establish sessions. Navy network administrators use ICMP extensively for connectivity testing
across NMCI and tactical networks.
Question 11 (Multiple-Choice)
A technician is configuring a shipboard network and needs to segment traffic between combat
systems and administrative networks. Which Layer 2 technology should be implemented?
A) NAT at Layer 3
B) VLAN tagging at Layer 2
C) Application proxy at Layer 7
