Chapter 21 — Network and communications security: service integration | Technologist Network and communications security

Open, free learning for anyone who wants to protect people and technology. No account is required to read this text or its worked answers.

Chapter 21 — Network and communications security: service integration

Lesson map

Lesson 21 published. Map, example, EX061.

flowchart TD
  N0["Learning outcomes"]
  N1["21.1 The learning platform"]
  N2["21.2 Managed printing"]
  N3["21.3 Heating controls"]
  N4["21.4 Change windows and communication"]
  N5["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5
  N5 --> EX["Worked example"]
  EX --> Q["Exercise EX061"]

Logical drawing

flowchart LR
  N0["Learning outcomes"]
  N1["21.1 The learning platform"]
  N2["21.2 Managed printing"]
  N3["21.3 Heating controls"]
  N4["21.4 Change windows and communication"]
  N5["Synthesis"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> Q["EX061"]

[Learning outcomes]
    |
    v
[21.1 The learning platform]
    |
    v
[21.2 Managed printing]
    |
    v
[21.3 Heating controls]
    |
    v
[21.4 Change windows and communication]
    |
    v
[Synthesis]
    |
    v
[Worked example] --> [Exercise EX061]

Learning outcomes

You will (1) integrate security with school services; (2) coordinate with suppliers; (3) keep services working through change.

21.1 The learning platform

The learning platform is hosted by a supplier on the internet and used by every student and teacher. After segmentation, Tomás confirms each zone that needs it can reach it: students, staff and remote VPN users. He checks that the platform's single sign-on works from every zone, since sign-on often depends on extra domains that are easy to miss. One missing domain in the DNS filter briefly blocks student logins during testing; adding it to the allowed list fixes the issue before term starts.

21.2 Managed printing

The managed print supplier monitors printer supplies and faults over the network. Its monitoring server must reach printers in the shared devices zone, but nothing else. Tomás and the supplier agree a narrow rule allowing their collection service to reach printers on the monitoring port only, with logging. The supplier also confirms which printer firmware updates they apply and when. Integrating suppliers this way lets them do their job without giving them wide access that would weaken the design. The rule is reviewed when the contract renews.

21.3 Heating controls

The heating company's direct remote access tool is replaced with access through the school VPN, using a named account for each engineer, reaching only the heating controller and logged. The company was initially reluctant, worried about delays in emergencies. Tomás and Gareth test the new path with the company's engineer, showing it takes under two minutes to connect. The contract is updated to require this path and notice of any changes. The scenario from chapter 13 is now addressed. The old remote access tool is uninstalled afterwards.

21.4 Change windows and communication

Integration changes happen in agreed windows, announced to staff and suppliers in advance with the expected effects and a contact for problems. Tomás drafts the announcements in plain language and Gareth sends them. After each window, a short note confirms what changed and lists any known issues. Regular, predictable communication builds confidence that the network team is careful, which in turn makes staff more willing to report problems early instead of improvising their own fixes. Announcements go out at least a week ahead, so teachers can plan lessons around any disruption.

Worked example

Three supplier services are integrated with narrow rules; the heating company moves to named VPN accounts.

Synthetic case. Suppliers are synthetic.

Errors and limits

Giving suppliers broad access to avoid integration work undermines segmentation.

Exercises

EX061 — Missing sign-on domain. What caused the brief student login failure? Rubric: 3 = sign-on domain missing from DNS allowed list;; 2 = missing domain;; 1 = platform outage;; 0 = none.
EX062 — Print supplier rule. What access does the print supplier receive? Rubric: 3 = only printers on monitoring port, logged;; 2 = printers;; 1 = full;; 0 = none.
EX063 — Heating reluctance. How was the heating company's reluctance addressed? Rubric: 3 = tested new path, under two minutes to connect;; 2 = demonstration;; 1 = forced;; 0 = none.

Synthesis

Careful integration lets school services and suppliers work within the secure design.

Continue studying — chapter 21 of 30

← Chapter 20 (draft) · Course chapter index · Chapter 22 (draft) →