This document offers a thorough lesson review and exam Q&A set from Lesson 4 of WGU’s D325 course (Emerging Technologies in Cybersecurity) for the 2025/2026 academic year, containing over 50 detailed questions and accurate answers. The material is designed to reinforce mastery of advanced networking topics, subnetting schemes, and IP configuration troubleshooting.
Core concepts include Classless Inter-Domain Routing (CIDR), IPv4 and IPv6 addressing, subnet masks, broadcast addresses, MAC address conflicts, ARP behavior, and IP conflict resolution. Learners will also gain a practical understanding of diagnostic commands like ipconfig, ifconfig, and arp -a, as well as tools for ping testing, gateway verification, and DNS flushing. The document includes real-world troubleshooting scenarios involving duplicate IP/MAC addresses, incorrect subnet masks, default gateway errors, and TCP/IP misconfigurations.
This review is highly beneficial for students in WGU's Cybersecurity and Networking programs, especially those preparing for unit exams, performance assessments, or certification-aligned evaluations in enterprise networking, IT operations, and system administration.
Recommended for:
WGU D325 Cybersecurity students
BSIT and Networking emphasis majors
Students preparing for CompTIA Network+ or Cisco exams
Network administrators and IT support trainees
Learners in subnetting and IP configuration modules
Keywords:
WGU D325 Lesson 4, IP troubleshooting, CIDR notation, subnetting quiz, IPv6 addressing, arp cache, duplicate MAC address, gateway issues, network design WGU, ipconfig vs ifconfig, DNS resolution, ping troubleshooting, broadcast address, switch port security, TCP/IP diagnostic tools
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WGU D325 Lesson 4.6.11 Lesson Review
& Module 4 2025/2026 Exam Questions
and Answers | 100% Solved
In a subnet with a /28 mask, why can't you rely solely on the first three
octets to determine if an IP address is within the same subnet? -
🧠ANSWER ✔✔Because the network prefix boundary lies within the last
octet
What is the first step in troubleshooting IP configuration issues if you have
ruled out problems at the Physical and Data Link layers? - 🧠ANSWER
✔✔Use ipconfig or ifconfig to verify the host configuration.
What issue arises when a host has an incorrect subnet mask that is longer
than it should be? - 🧠ANSWER ✔✔The host misroutes its replies, thinking
communicating hosts are on a different subnet.
, How can you identify machines with duplicate IP addresses? - 🧠ANSWER
✔✔Using ping and then arp -a to examine the ARP cache table
What is a likely cause of duplicate MAC addresses on a network? -
🧠ANSWER ✔✔Use of locally administered addressing
You are monitoring network traffic and notice that ARP requests for a
specific IP address are receiving responses from two different MAC
addresses.
What is the MOST likely cause of this issue, and how should you proceed
to troubleshoot it? - 🧠ANSWER ✔✔The IP address is configured on a
virtual machine and its host; reassign the IP address to only one device.
What should you suspect if you cannot ping a local host and the error is
"destination unreachable"? - 🧠ANSWER ✔✔Incorrect IP address or
netmask in the IP configuration
What is the first step in the general ping sequence for identifying
connectivity issues? - 🧠ANSWER ✔✔Ping the loopback address.
Why might pinging remote hosts fail even if the network configuration is
correct? - 🧠ANSWER ✔✔ICMP is blocked by a firewall or other security
software.