OpenCyber AcademyLesson map
Lesson 18. Map, example, EX064.
flowchart TD
E["Ellen can change router settings"] --> R["The provider owns the router"]
P["The payment company owns the reader"] --> C["Ellen contacts them"]
W["Wider routing controls"] --> N["Not a row in this checklist"]
Ownership decides who may change a box. It does not add a second shop.
Logical drawing
one shop, one router, one before-picture LAN
Ellen configures what the provider allows her to configure
card reader out of Leo's scope
not in the seven checks
BCP 38, RPKI, an IPsec tunnel, a zero-trust deployment
Learning outcomes
After this chapter, you should be able to:
- Keep the case to one shop and the printed device set.
- Say who acts on the provider's router and the payment company's reader.
- Locate BCP 38, routing security, IPsec, and zero trust outside this checklist.
18.1 A small router checklist is not the security architecture of the internet.
The case is one shop. Ellen owns the bakery. The internet provider owns the router, and Ellen can change its settings. The payment company owns and manages the card reader. Leo's scope lets him view router settings with Ellen present, export a device list, compare settings with a checklist, and adjust Wi-Fi and router settings only when Ellen approves each change. It excludes the card reader's internals, files on the office computer, and any change during opening hours. That scope is the authorisation boundary. A technically richer control that sits outside it is still outside it.
Several real controls sit outside it on purpose. RFC 2827, BCP 38, asks network operators to filter packets whose source addresses could not have come from the customer they arrived from. That is an edge duty of the provider, not a boolean in lab_router.py. NIST SP 800-189 and RFC 6480 concern inter-domain routing and an infrastructure for route authorisation. The bakery does not operate that routing. Saying the seven-line checklist "failed BCP 38" would report a test that was not run. Saying the provider "passed" it would report a result that was not given. The correct statement is that those controls are not this measurement.
IPsec, in RFC 4301 and NIST SP 800-77 Rev. 1, can protect packets between security gateways or hosts. The mobile-data idea for the card reader is a suggestion if the shop internet fails. It is not described as purchased, and it is not described as an IPsec tunnel. Zero trust, in NIST SP 800-207, is an architecture of explicit, per-request decisions. Guest isolation, even after the narrative turns it on, is one network control. It does not become that architecture because the fraction in a later story is seven of seven. IKEv2, RFC 7296, is the key-exchange companion of IPsec. No security association is recorded.
The device set stays the printed one plus the narrative names already given. No second shop, no staff roster, and no customer count are in the file. Leo remains the learner. Nadia remains the coach. Neither becomes a new device on the lease.
18.2 Worked example
Lesson table; scroll horizontally to read all columns →
| Control | Where it lives in this case | Decision |
|---|---|---|
| Router settings Ellen may change | In scope, with approval | May stay |
| Card-reader internals | Out of scope; she contacts the company | May stay |
| BCP 38 and route authorisation | Not measured here | Do not score them |
| A second branch | Not in the case | Do not add it |
Synthetic case. The provider and the payment company stay unnamed.
Errors and limits
Knowing a control exists is not the same as having run it, and not running it here is not a finding against an owner who was never asked.
Apply
- EX064 — Who owns the next action? The router belongs to the provider, the reader to the payment company, and the shop is one shop. Which of BCP 38, an IPsec tunnel, or a second branch does this checklist measure?
Show marking criteria
Rubric: 3 = none of those three; Ellen still contacts the provider or the payment company for their equipment; one shop and the printed device set stay; no staff roster or customer count is added;; 2 = those wider controls stay unmeasured and the shop stays one;; 1 = the ownership split only;; 0 = none.