arsenyeritsyan/nerworking

1. What this repository is

- This is a network architecture documentation suite, not an application codebase.

- The primary output is a curated set of Markdown documents, diagrams, labs, configs, cheat sheets, and PDFs for studying and documenting enterprise and service-provider networking.

2. Core knowledge layer

- The main architecture content lives in the numbered top-level documents 01_... through 08_....

- Each chapter is a standalone subsystem covering a major networking domain: overall architecture, OSI/protocol behavior, routing, security/VPNs, wireless roaming, multicast, VXLAN/EVPN fabrics, and SD-WAN vs Contrail.

3. Topic boundaries

- The repo is organized by network domain, not by implementation component.

- Each topic file acts as a boundary between conceptual documentation, vendor comparisons, and practical troubleshooting guidance.

- This makes the repository useful both as a learning path and as reference material for architecture design reviews.

4. Diagram subsystem

- diagrams/ is the visual backbone of the repo.

- It contains editable Draw.io diagram instructions/files for packet flows and topologies such as OSPF adjacency, BGP, EIGRP, IS-IS, RIP, multicast PIM, VXLAN EVPN, wireless roaming, and SD-WAN/Contrail.

- These diagrams connect the conceptual chapters to concrete message flows and topology layouts.

5. Lab and packet-capture subsystem

- 09_Labs_and_PacketCaptures/ is the hands-on environment layer.

- It includes GNS3/EVE-NG project files, device base configs, lab topology descriptions, and packet-capture walkthroughs.

- This is where the documentation is validated against observable protocol behavior and device configuration.

6. Representative lab topology content

- The lab set spans multiple domains: IPsec/IKEv2, multicast PIM-SM, wireless roaming, and SD-WAN vs Contrail.

- Base configs for routers, clients, controllers, WLCs, vBond/vSmart/vManage/vEdge, and other nodes indicate the repo is designed to model multi-node, multi-vendor network scenarios rather than isolated examples.

7. Cheat sheet subsystem

- 10_CheatSheets_PDF/ provides condensed operational references for BGP, OSPF, EIGRP, IS-IS, RIP, IPsec, multicast, VXLAN EVPN, SD-WAN, and wireless roaming.

- These are a separate delivery layer optimized for quick lookup, often derived from the deeper chapter content and diagrams.

8. Design-document layer

- design_docs/ holds higher-level architecture guidance, including Cisco Validated Design and vendor-neutral documentation.

- This forms the “reference architecture” layer of the repo, bridging conceptual theory and practical lab implementations.

9. Automation and repeatability

- automation/ contains Ansible/Terraform-style deployment support for lab setup or related provisioning workflows.

- deploy_lab.yml and inventory files suggest the repo can support reproducible lab builds, which is important for consistent demonstrations and training.

10. Supporting assets and localization

- The repo includes several standalone PDFs and a localized Armenian documentation branch under pdf in Armenian/.

- This indicates a content distribution model that supports multiple formats and audiences, not just source Markdown.

11. Primary data flow

- The typical flow is: chapter Markdown → diagrams → lab configs/projects → packet captures → PDF/cheat-sheet exports.

- Documentation is the source of truth; diagrams and labs are supporting artifacts that make the protocols and architectures observable and reproducible.

12. External tooling and execution boundaries

- The repo depends on external tools rather than a custom runtime: Pandoc or Markdown-to-PDF tooling, Draw.io/Visio for diagrams, GNS3/EVE-NG for labs, and Wireshark for PCAP analysis.

- There is no central application service; the architecture is a content pipeline and reference corpus built from interoperable documentation assets.

13. How to diagram this repo

- A good architecture diagram should show a central documentation core feeding three major consumers: visual diagrams, hands-on labs/PCAPs, and compressed cheat sheets.

- Around that, show tooling boundaries for export, diagram editing, and lab execution, with the top-level chapter files as the canonical source set.