D412 ITEC 3101 Network Analytics &
Troubleshooting
Final Assessment Review
(Questions & Solutions)
2025
©2025
, 1. Case Study – Packet Loss Diagnosis
A network engineer is troubleshooting intermittent connectivity issues
on a corporate LAN. Using Wireshark, she observes a significant number
of fragmented TCP segments and retransmitted packets.
Question: Which network issue is most likely contributing to these
symptoms?
A. High network latency
B. Packet loss due to congestion
C. Malfunctioning DNS
D. Incorrect MTU settings
ANS: D. Incorrect MTU settings
Rationale: Fragmentation and subsequent retransmissions often
indicate mismatched Maximum Transmission Unit (MTU) sizes. When
packets exceed the interface’s MTU, they are fragmented, which, if not
managed properly, can lead to packet loss and retransmissions.
---
2. Case Study – Latency Analysis with Traceroute
A data center experiences increased application response times during
peak hours. A network engineer runs traceroute tests and notices an
unusual delay between two intermediate routers.
Question: What does this finding most likely indicate?
A. A physical cable cut in the network
B. Congestion or suboptimal routing between those routers
C. A DNS resolution error
D. Malware infection on an endpoint
ANS: B. Congestion or suboptimal routing between those routers
Rationale: Delays in traceroute output between specific hops suggest
congestion or inefficient routing on that link, affecting overall network
©2025
, latency.
---
3. Case Study – Flow Analytics Application
An organization deploys a NetFlow collector to analyze network traffic
patterns. The security team observes a sudden surge in outbound traffic
from a single subnet.
Question: What could be the potential cause for this anomaly?
A. A routine software update
B. A misconfigured router
C. A Distributed Denial-of-Service (DDoS) attack from within the network
D. Scheduled data backups
ANS: C. A Distributed Denial-of-Service (DDoS) attack from within the
network
Rationale: A sudden surge in outbound traffic, especially if unexpected
and concentrated in one subnet, can indicate a compromised node
participating in a DDoS attack or exfiltrating data. Flow data provides
insight into traffic volume and source anomalies.
---
4. Case Study – DNS Resolution Troubleshooting
Users in a corporate network report that webpages are intermittently
inaccessible. The network engineer uses tools such as dig and nslookup
and finds prolonged response times from the local DNS server.
Question: Which issue is most likely responsible for these DNS
resolution delays?
A. Faulty firewall settings
B. Overloaded or improperly configured DNS caching
C. Outdated SSL certificates
D. Bandwidth limitations on the network
ANS: B. Overloaded or improperly configured DNS caching
Rationale: Delays in DNS lookup responses typically result from issues
with the DNS server’s performance or caching mechanisms, leading to
©2025
Troubleshooting
Final Assessment Review
(Questions & Solutions)
2025
©2025
, 1. Case Study – Packet Loss Diagnosis
A network engineer is troubleshooting intermittent connectivity issues
on a corporate LAN. Using Wireshark, she observes a significant number
of fragmented TCP segments and retransmitted packets.
Question: Which network issue is most likely contributing to these
symptoms?
A. High network latency
B. Packet loss due to congestion
C. Malfunctioning DNS
D. Incorrect MTU settings
ANS: D. Incorrect MTU settings
Rationale: Fragmentation and subsequent retransmissions often
indicate mismatched Maximum Transmission Unit (MTU) sizes. When
packets exceed the interface’s MTU, they are fragmented, which, if not
managed properly, can lead to packet loss and retransmissions.
---
2. Case Study – Latency Analysis with Traceroute
A data center experiences increased application response times during
peak hours. A network engineer runs traceroute tests and notices an
unusual delay between two intermediate routers.
Question: What does this finding most likely indicate?
A. A physical cable cut in the network
B. Congestion or suboptimal routing between those routers
C. A DNS resolution error
D. Malware infection on an endpoint
ANS: B. Congestion or suboptimal routing between those routers
Rationale: Delays in traceroute output between specific hops suggest
congestion or inefficient routing on that link, affecting overall network
©2025
, latency.
---
3. Case Study – Flow Analytics Application
An organization deploys a NetFlow collector to analyze network traffic
patterns. The security team observes a sudden surge in outbound traffic
from a single subnet.
Question: What could be the potential cause for this anomaly?
A. A routine software update
B. A misconfigured router
C. A Distributed Denial-of-Service (DDoS) attack from within the network
D. Scheduled data backups
ANS: C. A Distributed Denial-of-Service (DDoS) attack from within the
network
Rationale: A sudden surge in outbound traffic, especially if unexpected
and concentrated in one subnet, can indicate a compromised node
participating in a DDoS attack or exfiltrating data. Flow data provides
insight into traffic volume and source anomalies.
---
4. Case Study – DNS Resolution Troubleshooting
Users in a corporate network report that webpages are intermittently
inaccessible. The network engineer uses tools such as dig and nslookup
and finds prolonged response times from the local DNS server.
Question: Which issue is most likely responsible for these DNS
resolution delays?
A. Faulty firewall settings
B. Overloaded or improperly configured DNS caching
C. Outdated SSL certificates
D. Bandwidth limitations on the network
ANS: B. Overloaded or improperly configured DNS caching
Rationale: Delays in DNS lookup responses typically result from issues
with the DNS server’s performance or caching mechanisms, leading to
©2025
