Chapter 38 — Capstone implementation | Bachelor's Network and communications security

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Chapter 38 — Capstone implementation

Lesson map

Lesson 38 published. Map, example, EX112.

flowchart TD
  N0["Learning outcomes"]
  N1["38.1 Deployment days"]
  N2["38.2 On-site verification"]
  N3["38.3 Issues found"]
  N4["38.4 Supplier coordination"]
  N5["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5
  N5 --> EX["Worked example"]
  EX --> Q["Exercise EX112"]

Logical drawing

flowchart LR
  N0["Learning outcomes"]
  N1["38.1 Deployment days"]
  N2["38.2 On-site verification"]
  N3["38.3 Issues found"]
  N4["38.4 Supplier coordination"]
  N5["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> Q["EX112"]

[Learning outcomes]
    |
    v
[38.1 Deployment days]
    |
    v
[38.2 On-site verification]
    |
    v
[38.3 Issues found]
    |
    v
[38.4 Supplier coordination]
    |
    v
[Synthesis]
    |
    v
[Worked example] --> [Exercise EX112]

Learning outcomes

You will (1) deploy the design at two clinics; (2) verify on site; (3) handle issues.

38.1 Deployment days

On two Saturdays, Priya and the IT lead deploy the full design at the two clinics. They follow the rehearsed checklist: save existing configurations, configure the management network, update access points with the staff and clinical networks, install the firewall with the approved rules, enable logging and run the on-site tests. The first clinic takes three and a half hours, slightly longer than the lab rehearsal because two access points need firmware updates. The second takes under three hours. Each step is ticked off and timed on the checklist.

38.2 On-site verification

On-site tests repeat the lab tests in the real environment, with the clinics' permission and outside opening hours. Guest test devices cannot reach staff, clinical or management groups; staff devices reach the booking service and files; clinical carts reach the lab results server; and the management zone is reachable only from the administrator workstation. All tests pass at both clinics, and results are recorded with times and configuration versions for the evidence file. Any failure would trigger the rehearsed rollback at the decision point, so services return quickly while the cause is investigated.

38.3 Issues found

The first week brings three issues. A clinical cart model fails to connect because it does not support the certificate method; it is placed on the clinical network using its restricted fallback, which allows only its specific flow. A staff member forgets her new wireless password and is reset by the IT lead. And denied logs show a staff laptop trying to reach a clinical cart every morning, which turns out to be an old shortcut to a retired application, removed after checking with the user.

38.4 Supplier coordination

The lab results supplier upgrades its service to TLS 1.3 during the capstone, as agreed. Priya reruns the TLS audit and confirms the change. The supplier also agrees to connect for maintenance only through the VPN with a named account. Coordinating with suppliers takes time and depends on their schedules, so Priya had planned for delay; in this case it arrived on time, but the plan would have allowed her to report it as pending without undermining the rest of the capstone.

Worked example

Both clinics are deployed; all on-site tests pass; three issues in the first week are resolved within a day each.

Synthetic case. Deployment is synthetic.

Errors and limits

Assuming every device supports the chosen authentication method causes deployment-day failures.

Exercises

EX112 — Unsupported cart. How was the cart that could not use certificates handled? Rubric: 3 = restricted fallback allowing only its flow;; 2 = fallback;; 1 = removed;; 0 = none.
EX113 — Morning denies. What caused the daily denied laptop-to-cart connections? Rubric: 3 = old shortcut to retired application;; 2 = shortcut;; 1 = attack;; 0 = none.
EX114 — TLS confirmation. How was the supplier's TLS upgrade confirmed? Rubric: 3 = rerunning the TLS audit script;; 2 = audit;; 1 = told;; 0 = none.

Synthesis

Careful, rehearsed deployment with on-site verification and quick issue handling delivers the design safely.

Continue studying — chapter 38 of 40

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