CCDE v3.1 Practical - Study Vault (AI Infrastructure elective)

This is an Obsidian vault built to prepare for the CCDE v3.1 Practical exam, with the AI Infrastructure elective as the focus. It is a single-hub system: capture, visual review, and spaced repetition all live in Obsidian. No MindNode, no separate Anki app.

Important: The exam tests judgment, not recall

The Practical scores your ability to recommend, justify, design, validate, optimize, and adapt designs under stated requirements. So almost every note here is written in one shape: requirement -> constraints -> options -> tradeoffs -> recommendation -> justification -> what would change it. Build the reasoning, not the trivia.

Folder map

• 00 Maps of Content/ - the three entry points (Exam Topics (Design Lenses) - MOC, CCDE Core - MOC, AI Infrastructure - MOC). Start here when studying.
• 01 Design lenses (Exam Topics)/ - the five design domains plus a common-design-traps note: how to read a scenario (the layer above the technology notes). Read these first - they tie everything together.
• Core/ - the eight Core technology areas (Transport, L2 control plane, L3 control plane, Data plane, Virtualization, Security, Wireless, Automation).
• AI Infrastructure/ - the elective notes (highest priority - books barely cover this).
• Study-ops/ - the whole-day Practical exam-day approach plus the per-scenario intake checklist.
• _templates/ - the two note templates (see below).
• _attachments/ - PNG comparison matrices and decision trees, embedded into notes.

Two note types

1. Design Decision (type: design-decision) - for any "which option, and why" topic

   (e.g. Ethernet vs InfiniBand). Carries a comparison matrix + a decision tree. This is the workhorse and the part that wins exam points.

2. Concept (type: concept) - for "what is X / how does X work" atomic notes

   (e.g. DCQCN). Lighter; feeds the decisions.

Duplicate a file from _templates/ to start a new note (or set Obsidian's Templates core plugin folder to _templates).

Conventions

• Frontmatter on every note: domain (Core | AI-Infra), blueprint-ref (the exam list ID),

  type, status (stub | draft | complete), and tags.

• Status workflow: stub (just a placeholder + link target) -> draft (content in) ->

  complete (matrix/tree done, cards written, validated). Query status: stub to see what's left.

• Tradeoff tags are the cross-cutting axis the exam cares about:

  #tradeoff/cost #tradeoff/latency #tradeoff/scale #tradeoff/lock-in #tradeoff/operability #tradeoff/power. Tag every decision with the axes in play.

• Links (`[[wikilink]]`) connect a decision to its underlying concepts. Unresolved

  (greyed) links are normal - they are the to-do list and they populate the graph.

• Embeds (`![[file.png]]`) pull a matrix/tree into a note. Obsidian finds the image by

  filename anywhere in the vault, so _attachments/ location is fine.

Spaced repetition (inside Obsidian)

The cards are reviewed by the Spaced Repetition community plugin (by st3v3nmw), which uses FSRS (the same modern algorithm Anki uses) and keeps cards inside the note, in context.

Setup (once): Settings -> Community plugins -> turn off Restricted mode -> Browse -> install & enable Spaced Repetition -> in its settings set Flashcard tags to #flashcards (or enable "convert folders/all notes").

Card syntax used in this vault:

• Basic: Question::Answer - written as its own line (not a bullet).
• Cloze: wrap the hidden part in highlight.
• Formatting rule: put one blank line between every card. The plugin needs blank lines

  around cloze cards or a card will swallow its neighbours. Keep the #flashcards tag on its own line with a blank line after it. (So: bare lines, blank-line separated - not a bullet list.)

Visual review (mind-map style, native)

For an at-a-glance map of a domain, use either:

• the Canvas core plugin (drag note cards onto an infinite canvas - they stay live), or
• a community Mind Map plugin, which renders a note's headings as an interactive map.

  Either keeps the map in sync with the notes as we edit them. The hand-designed PNG matrices / trees in _attachments/ embed into both.

What's in the vault

• Glossary - one-line A-Z definitions, every term linked to its owning note.
• Blueprint coverage map - every blueprint line mapped to the note(s) that own it.

  Complete - the full blueprint is covered:

• Five design-lens notes (Exam Topics domains 1-5) - the reasoning layer above the technology, each linking down into the notes it governs.
• 60 Core notes across all eight technology areas; each design decision carries a comparison matrix and/or a decision tree, plus spaced-repetition cards.
• 24 AI Infrastructure notes across all four sections (fundamentals & governance; network; security; compute, storage & environment) - the elective, in study order.
• 20 comparison matrices / decision trees in _attachments/, embedded into the relevant notes.
• Three MOCs, both templates, and the per-scenario intake checklist.
• Every wikilink resolves (no broken links); every design note follows the requirement -> constraints -> options -> tradeoffs -> recommendation -> justification -> what-would-change shape and carries cards.

Optional next steps (not required - the blueprint is fully covered):

• Fold in book-specific cross-references as you upload your Cisco Press titles: map each chapter to the blueprint line items and merge the reasoning into the matching notes, de-duplicating where two books overlap so the system stays consistent.
• Add a study-sequence / scenario-practice set if you want guided drills against the five lenses.