WGU D315 — Network and Security
Foundations | 250 Practice Exam Questions ,
Answers & Rationales
WGU D315 EXAM QUICK REFERENCE
Section Questions Core Topics
LAN, WAN, MAN, PAN, SAN, VPN, CAN, VLAN
Network Types & Topologies 1–25
— star, mesh, bus, ring, hybrid
All 7 layers — protocols, devices, PDUs,
The OSI Model (7 Layers) 26–55
encapsulation
TCP/IP Model, Protocols & TCP/IP 4-layer model, port numbers, protocols,
56–90
Hardware network commands, cabling
CIA Triad & AAA Confidentiality, Integrity, Availability,
91–115
Framework Authentication, Authorization, Accounting
Cybersecurity Attacks & Attack types, malware, encryption, firewalls, IDS/IPS,
116–170
Countermeasures wireless security
Firewalls, DMZ, VPN, subnetting/IPv4/IPv6, incident
Network Security Solutions 171–250
response, forensics, compliance
SECTION 1: BASIC NETWORK SYSTEMS & CONCEPTS (Q1–90)
Part A: Network Types & Topologies (Q1–25)
1. Which type of network is designed to connect devices within a single home,
office, or small geographic area?
A) WAN B) MAN C) LAN ✅ (correct answer) D) SAN
Rationale: A Local Area Network (LAN) connects devices within a limited
geographic area such as a home, office building, or school. LANs typically use
Ethernet or Wi-Fi technologies and are privately owned. WANs span large
geographic areas, MANs cover metropolitan areas, and SANs are specialized
storage networks.
,2. A company with offices in New York, London, and Tokyo connects all three
locations over a private leased line network. This is an example of a:
A) LAN B) MAN C) VLAN D) WAN ✅ (correct answer)
Rationale: A Wide Area Network (WAN) spans large geographic distances —
typically connecting LANs across cities, countries, or continents. The internet
itself is the largest WAN. Private leased lines, MPLS, and VPN tunnels over
the internet are all WAN technologies used by businesses for multi-site
connectivity.
3. A Metropolitan Area Network (MAN) typically covers the geographic scope of:
A) A single building B) A city or campus ✅ (correct answer) C) Multiple
continents D) A single room
Rationale: A MAN (Metropolitan Area Network) spans a geographic area
roughly the size of a city or large campus — larger than a LAN but smaller
than a WAN. MANs are often used by ISPs to connect customers within a
metropolitan region, or by organizations connecting multiple campuses within
the same city.
4. A Personal Area Network (PAN) most commonly uses which wireless
technology to connect devices within approximately 10 meters?
A) Wi-Fi (802.11) B) LTE/5G cellular C) Bluetooth ✅ (correct answer) D)
Ethernet
Rationale: A PAN (Personal Area Network) connects devices in immediate
personal proximity — typically within 10 meters. Bluetooth is the most
common PAN technology, connecting devices like headphones, smartwatches,
keyboards, and mice to a smartphone or computer. PANs can also use
infrared (IrDA) or near-field communication (NFC).
,5. In which network topology does every device connect directly to every other
device, providing maximum redundancy?
A) Star B) Ring C) Bus D) Mesh ✅ (correct answer)
Rationale: In a full mesh topology, every node has a direct point-to-point
connection to every other node. This provides maximum redundancy (any
single link failure does not disrupt connectivity) but is the most expensive and
complex topology due to the large number of connections required: n(n-1)/2
links for n devices.
6. A star topology's central connecting device is most commonly a:
A) Hub or switch ✅ (correct answer) B) Router C) Modem D) Repeater
Rationale: In a star topology, all devices connect to a central hub or switch.
Each device has a dedicated connection to the central device. Switches are
preferred over hubs in modern star networks because switches intelligently
forward frames only to the intended recipient port, reducing collisions and
improving performance.
7. Which network topology is most susceptible to a single point of failure that can
bring down the entire network?
A) Mesh B) Star ✅ (correct answer) C) Ring D) Hybrid
Rationale: In a star topology, the central switch or hub is a single point of
failure — if it fails, all connected devices lose network connectivity. While
individual device failures in a star topology only affect that device, the central
device failure disrupts all devices. This is a key disadvantage of the star
topology.
8. In a bus topology, all devices share a single communication channel called the:
A) Ring B) Backbone ✅ (correct answer) C) Switch fabric D) Segment bridge
, Rationale: In a bus topology, all devices are connected to a single shared
communication medium (the backbone or trunk cable). Data transmitted by
any device travels in both directions along the bus and is received by all
devices — but only the intended recipient processes it. Bus topologies are
largely obsolete, replaced by star/switch topologies.
9. A Virtual LAN (VLAN) is used primarily to:
A) Extend network coverage beyond physical building boundaries B) Logically
segment a network into separate broadcast domains regardless of physical location
✅ (correct answer) C) Convert analog signals to digital for transmission D)
Connect two different types of network media
Rationale: VLANs logically divide a physical network into separate broadcast
domains without requiring physical separation. Devices in different VLANs
cannot communicate directly without a router or Layer 3 switch. VLANs
improve security, reduce unnecessary broadcast traffic, and allow flexible
network management regardless of physical device location.
10. A Storage Area Network (SAN) is specialized for:
A) Providing wireless access to the internet B) Connecting storage devices to
servers, providing high-speed, block-level access to storage ✅ (correct answer)
C) Connecting personal devices in a home environment D) Providing telephony
services across large geographic areas
Rationale: A SAN is a dedicated high-speed network that provides servers
with block-level access to centralized storage devices (disk arrays, tape
libraries). SANs typically use Fibre Channel or iSCSI protocols and are
common in enterprise data centers where high-performance, reliable storage
access is critical.
11. Which network type provides employees with secure remote access to their
company's internal network over the public internet?
Foundations | 250 Practice Exam Questions ,
Answers & Rationales
WGU D315 EXAM QUICK REFERENCE
Section Questions Core Topics
LAN, WAN, MAN, PAN, SAN, VPN, CAN, VLAN
Network Types & Topologies 1–25
— star, mesh, bus, ring, hybrid
All 7 layers — protocols, devices, PDUs,
The OSI Model (7 Layers) 26–55
encapsulation
TCP/IP Model, Protocols & TCP/IP 4-layer model, port numbers, protocols,
56–90
Hardware network commands, cabling
CIA Triad & AAA Confidentiality, Integrity, Availability,
91–115
Framework Authentication, Authorization, Accounting
Cybersecurity Attacks & Attack types, malware, encryption, firewalls, IDS/IPS,
116–170
Countermeasures wireless security
Firewalls, DMZ, VPN, subnetting/IPv4/IPv6, incident
Network Security Solutions 171–250
response, forensics, compliance
SECTION 1: BASIC NETWORK SYSTEMS & CONCEPTS (Q1–90)
Part A: Network Types & Topologies (Q1–25)
1. Which type of network is designed to connect devices within a single home,
office, or small geographic area?
A) WAN B) MAN C) LAN ✅ (correct answer) D) SAN
Rationale: A Local Area Network (LAN) connects devices within a limited
geographic area such as a home, office building, or school. LANs typically use
Ethernet or Wi-Fi technologies and are privately owned. WANs span large
geographic areas, MANs cover metropolitan areas, and SANs are specialized
storage networks.
,2. A company with offices in New York, London, and Tokyo connects all three
locations over a private leased line network. This is an example of a:
A) LAN B) MAN C) VLAN D) WAN ✅ (correct answer)
Rationale: A Wide Area Network (WAN) spans large geographic distances —
typically connecting LANs across cities, countries, or continents. The internet
itself is the largest WAN. Private leased lines, MPLS, and VPN tunnels over
the internet are all WAN technologies used by businesses for multi-site
connectivity.
3. A Metropolitan Area Network (MAN) typically covers the geographic scope of:
A) A single building B) A city or campus ✅ (correct answer) C) Multiple
continents D) A single room
Rationale: A MAN (Metropolitan Area Network) spans a geographic area
roughly the size of a city or large campus — larger than a LAN but smaller
than a WAN. MANs are often used by ISPs to connect customers within a
metropolitan region, or by organizations connecting multiple campuses within
the same city.
4. A Personal Area Network (PAN) most commonly uses which wireless
technology to connect devices within approximately 10 meters?
A) Wi-Fi (802.11) B) LTE/5G cellular C) Bluetooth ✅ (correct answer) D)
Ethernet
Rationale: A PAN (Personal Area Network) connects devices in immediate
personal proximity — typically within 10 meters. Bluetooth is the most
common PAN technology, connecting devices like headphones, smartwatches,
keyboards, and mice to a smartphone or computer. PANs can also use
infrared (IrDA) or near-field communication (NFC).
,5. In which network topology does every device connect directly to every other
device, providing maximum redundancy?
A) Star B) Ring C) Bus D) Mesh ✅ (correct answer)
Rationale: In a full mesh topology, every node has a direct point-to-point
connection to every other node. This provides maximum redundancy (any
single link failure does not disrupt connectivity) but is the most expensive and
complex topology due to the large number of connections required: n(n-1)/2
links for n devices.
6. A star topology's central connecting device is most commonly a:
A) Hub or switch ✅ (correct answer) B) Router C) Modem D) Repeater
Rationale: In a star topology, all devices connect to a central hub or switch.
Each device has a dedicated connection to the central device. Switches are
preferred over hubs in modern star networks because switches intelligently
forward frames only to the intended recipient port, reducing collisions and
improving performance.
7. Which network topology is most susceptible to a single point of failure that can
bring down the entire network?
A) Mesh B) Star ✅ (correct answer) C) Ring D) Hybrid
Rationale: In a star topology, the central switch or hub is a single point of
failure — if it fails, all connected devices lose network connectivity. While
individual device failures in a star topology only affect that device, the central
device failure disrupts all devices. This is a key disadvantage of the star
topology.
8. In a bus topology, all devices share a single communication channel called the:
A) Ring B) Backbone ✅ (correct answer) C) Switch fabric D) Segment bridge
, Rationale: In a bus topology, all devices are connected to a single shared
communication medium (the backbone or trunk cable). Data transmitted by
any device travels in both directions along the bus and is received by all
devices — but only the intended recipient processes it. Bus topologies are
largely obsolete, replaced by star/switch topologies.
9. A Virtual LAN (VLAN) is used primarily to:
A) Extend network coverage beyond physical building boundaries B) Logically
segment a network into separate broadcast domains regardless of physical location
✅ (correct answer) C) Convert analog signals to digital for transmission D)
Connect two different types of network media
Rationale: VLANs logically divide a physical network into separate broadcast
domains without requiring physical separation. Devices in different VLANs
cannot communicate directly without a router or Layer 3 switch. VLANs
improve security, reduce unnecessary broadcast traffic, and allow flexible
network management regardless of physical device location.
10. A Storage Area Network (SAN) is specialized for:
A) Providing wireless access to the internet B) Connecting storage devices to
servers, providing high-speed, block-level access to storage ✅ (correct answer)
C) Connecting personal devices in a home environment D) Providing telephony
services across large geographic areas
Rationale: A SAN is a dedicated high-speed network that provides servers
with block-level access to centralized storage devices (disk arrays, tape
libraries). SANs typically use Fibre Channel or iSCSI protocols and are
common in enterprise data centers where high-performance, reliable storage
access is critical.
11. Which network type provides employees with secure remote access to their
company's internal network over the public internet?
