Complete Study Guide to Pass OA - C172 Network and Security Foundations

WGU Course D315 (C172) Study Guide


July 27, 2025



Contents
1 Introduction to Networking Concepts . . . . . . . . . . . . . . . . . . . . 2
1.1 Networking Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Network Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Network Topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Network Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5 Network Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.6 OSI Model & TCP/IP Model . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.7 Virtual and Cloud Computing . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Introduction to Networking Security . . . . . . . . . . . . . . . . . . . . . 6
2.1 Network Security Overview . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Confidentiality, Integrity, and Availability (CIA) Triad . . . . . . . . . 7
3 Network Security Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Security Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Firewalls, IDS, and IPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Encryption Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.4 Attacks and Mitigations . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.5 Wireless Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.6 Cloud Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.7 User Authentication and Access Control . . . . . . . . . . . . . . . . . 10
3.8 Security Governance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11




1

, 1 Introduction to Networking Concepts
1.1 Networking Devices
Device Layer What does the device do?
Hub 1 Broadcasts data to all connected
devices.
Repeater 1 Amplifies and regenerates signals to
extend network range.
Switch 2 Forwards data to specific devices based
on MAC addresses.
Wireless Access 2 Connects wireless devices to a wired
Point (WAP) network.
Bridge 2 Connects two network segments,
filtering traffic by MAC addresses.
Wireless Range 2 Extends the range of a wireless
Extender network by repeating signals.
Router 3 Routes data between networks based
on IP addresses.
Modem 1 Converts digital signals to analog (and
vice versa) for internet connectivity.
Firewall 3/7 Filters network traffic based on security
rules to protect networks.

1.2 Network Types
• Personal Area Network (PAN): Small-scale network for personal devices
(e.g., Bluetooth, 10m range).

• Local Area Network (LAN): Connects devices in a small area (e.g., office,
home).

• Wireless Local Area Network (WLAN): LAN using wireless connections
(e.g., Wi-Fi).

• Campus Area Network (CAN): Interconnects LANs within a campus or
university.

• Metropolitan Area Network (MAN): Spans a city, connecting multiple LANs.

• Wide Area Network (WAN): Covers large geographic areas (e.g., internet,
corporate networks).

• Storage Area Network (SAN): High-speed network for storage devices, en-
abling data access.

1.3 Network Topologies
• Bus: Devices connect to a single cable; simple but prone to collisions.

• Ring: Devices form a closed loop; data travels in one direction.

2