Unit 3 Case Files — Securing Networks

Unit 3 — Securing Networks. You are working three independent case files this unit, each dropping you into a different network security role. Read each scenario carefully, work through the embedded evidence tables, and answer every question in your own words.

Your answers autosave to this browser as you type — nothing is transmitted anywhere. When you're finished, use Export My Case File to download a text file for submission.

CASE 2026-3A

Adams County Hospital · Network Security Engineering

Protecting Patient Medical Data

Infrastructure Risk

You are a network security engineer at Adams County Hospital. The hospital runs two critical systems: a public-facing web application that lets patients book appointments and pay bills, and an internal file server that stores patient medical records.

Administration has approved the purchase of two new firewalls. Your job is to determine where each firewall should sit in the network and how each protected server should be configured. Below is the current network segment inventory your team compiled during the site survey.

Evidence: Network Segment Inventory

Click a segment's firewall assignment to cycle through options: Unassigned → Firewall A (Perimeter) → Firewall B (Internal Segmentation) → Both Firewalls.

Segment / Asset	Data Sensitivity	Current Exposure	Firewall Assignment
Patient Portal Web Server (booking & scheduling)	Low–Moderate (contact info, appointment data)	Internet-facing (DMZ)	— Unassigned —click to set
Bill Pay / Payment Processing Interface	High (cardholder data)	Internet-facing (DMZ)	— Unassigned —click to set
Internal Patient Records File Server (PHI)	Critical (protected health information)	Internal LAN only	— Unassigned —click to set
Staff Workstation Network	Moderate (staff credentials, EHR access)	Internal LAN only	— Unassigned —click to set
Guest / Patient Wi-Fi	Low (no hospital data access)	Internet-facing, physically inside building	— Unassigned —click to set

Questions

1Using the table above, explain your firewall placement for each segment. Why does the internal records server need different treatment than the patient portal?

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2What specific configuration would you apply to Firewall A (the perimeter firewall) — e.g., which ports/protocols should it allow inbound, and what should it block by default?

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3What specific configuration would you apply to Firewall B (internal segmentation) to isolate the patient records server from the rest of the internal network?

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4Patient records fall under HIPAA. Identify one specific HIPAA safeguard requirement and explain how your firewall configuration helps satisfy it.

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5What logging or monitoring would you enable on each firewall so the hospital can detect an intrusion attempt after the fact?

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CASE 2026-3B

Emergency Shelter Deployment · National Guard Network Technician

Configuring a Secure Wireless Network

Wireless Exposure

In the aftermath of a natural disaster, you've been called up as a network technician to set up a wireless network at the local high school gymnasium, now converted into an emergency shelter. A satellite uplink provides internet access. Displaced residents need connectivity to reach family and friends.

Your job is to configure the network so it's safe to use in a crowded, unvetted public setting — and to be able to detect malicious activity on a network you can't fully control who joins. Below is a snapshot of the device connection log from the first evening of operation.

Evidence: Device Connection Log

Click a row to flag it as suspicious. Flag every entry you believe warrants investigation.

Timestamp	Device Name	MAC Address	Session Length	Data Transferred
18:02:11	Samsung-Galaxy-A14	3C:A6:F2:__:__:8B	42 min	18 MB
18:07:44	iPhone-Maria	A4:5E:60:__:__:2D	1 hr 10 min	64 MB
18:15:02	DESKTOP-UNKNOWN	00:1A:2B:__:__:9F	3 min	2 MB
19:30:55	Android-Device-7F3A	3C:A6:F2:__:__:8B	4 hrs 20 min	3 MB
21:48:19	unknown-device	DE:AD:BE:__:__:00	6 min	4.2 GB
22:10:03	Kids-Tablet	88:B1:11:__:__:C4	55 min	210 MB
02:14:37	unknown-device	DE:AD:BE:__:__:01	11 min	3.9 GB
07:02:50	Laptop-Guest12	F0:99:B6:__:__:77	28 min	15 MB

Questions

1Describe the wireless configuration you would implement: SSID setup, encryption standard, and authentication approach for a shared, publicly-accessible network like this one.

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2Using the connection log, which entries did you flag as suspicious, and why? Reference specific fields (timestamp, MAC address pattern, data volume) in your justification.

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3Recommend a set of detective controls (e.g., IDS/IPS, connection logging, alert thresholds) to monitor this network going forward.

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4What is the impact of the detective controls you recommended — on network performance, on shelter residents' usability/privacy, and on your team's ability to respond quickly?

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5Satellite bandwidth is limited and shared by everyone in the shelter. How does that constraint change or limit your security recommendations above?

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CASE 2026-3C

Naval Submarine Operations · Network Technician

Protecting a Network on a Naval Submarine

Segmentation Critical

You manage three separate LANs aboard a naval submarine:

A dedicated LAN for weapons systems
A secure LAN for official naval operations
A LAN for crew recreation

Each LAN carries a different level of risk if compromised, and each is used by a different mix of personnel. Your job is to recommend a security posture for each LAN and define exactly who should be able to reach what.

Evidence: LAN Access Control Matrix

Click a cell to cycle its access level: No Access → Monitored / Restricted → Full Access → No Access.

LAN	Weapons Officer	Command Staff	General Crew	External / Internet Gateway
Weapons Systems LAN Fire control, targeting	No Access	No Access	No Access	No Access
Official Operations LAN Navigation, comms, orders	No Access	No Access	No Access	No Access
Crew Recreation LAN Entertainment, personal use	No Access	No Access	No Access	No Access

Questions

1Recommend security features for each of the three LANs individually (e.g., isolation level, encryption, physical/network separation). Explain your reasoning for each.

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2Explain the access levels you assigned in the matrix above. Justify any cell where you gave a role more than "No Access" to the Weapons Systems LAN.

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3Why does the Weapons Systems LAN require the strictest isolation of the three? What specific failure could occur if it were connected to the Crew Recreation LAN, even indirectly?

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4Describe, in words, a network diagram that demonstrates your recommended security features — name each LAN, show which are physically or logically separated, where any gateway or monitoring device sits, and label the direction data is allowed to flow.

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Case Files: Securing Networks

Protecting Patient Medical Data

Evidence: Network Segment Inventory

Questions

Configuring a Secure Wireless Network

Evidence: Device Connection Log

Questions

Protecting a Network on a Naval Submarine

Evidence: LAN Access Control Matrix

Questions

Clear all responses?