┏┓╻┏━╸╺┳╸╺┳╸┏━┓┏━┓┏━╸┏━╸┏━┓
┃┗┫┣╸  ┃  ┃ ┣┳┛┣━┫┃  ┣╸ ┣┳┛
╹ ╹┗━╸ ╹  ╹ ╹┗╸╹ ╹┗━╸┗━╸╹┗╸
Cisco IOS & STP Simulation in Java

A terminal UI that emulates a slice of Cisco-style IOS for switch-only labs: add switches, wire ports, assign costs, compute MST, trace paths, and send ICMP-like pings, all implemented with custom Data Structures & Algorithms.

Course context: University of Mataram — Algorithms & Data Structures / 2025.

Licensed under the MIT License.

---

✨ What makes NetTracer different

• Real networking concept: focuses on STP (loop-free logical topology on a loopy physical graph).
• DSA-first: custom LinkedList, Stack, PriorityQueue, Graph arrays, Merge Sort, Union-Find, BFS/Dijkstra.
• IOS-like CLI: show, add-link, set-priority, ping, show ascii mst, etc.
• ASCII Topology Renderer: scalable circular layout, rectangular switch boxes, edge connectors from box boundaries, MST/shortest-path highlighting.

---

🧩 Libraries / Modules Used

Category	Module	Notes
Standard	java.lang	Implicit (String, Math, etc.)
	java.util.Scanner	Only in CLI shell for input
Custom DSA	Topology/LinkedList.java	Port/link index lists per switch
	CLI/Stack.java	Command history (undo/redo infra)
	PDU/PriorityQueue.java	Event scheduler for ping PDUs
	Topology/Graph.java	Parallel arrays: switches, links, costs, up/down
Algorithms	Merge Sort	Edge cost sorting (Kruskal)
	Union-Find	MST building
	BFS / Dijkstra O(n²)	Path finding for ping + ASCII path view

Core modules intentionally avoid java.util collections to highlight DSA implementation.

---

⚙️ Build & Run

Option A — Plain Java (recommended)

# From repo root
javac -encoding UTF-8 -d bin \
  src/CLI/*.java \
  src/CLI/*/*.java \
  src/Commands/*/*.java \
  src/Engine/*.java \
  src/PDU/*.java \
  src/Topology/*.java \
  src/Utils/*.java \
  src/MAIN_App.java

java -cp bin MAIN_App

Option B — VS Code

• Use the provided .vscode/launch.json and settings.json.
• Ensure file encoding is UTF-8 (for box-drawing in ASCII UI).

Option C — Termux / Linux

pkg install openjdk-17
javac -encoding UTF-8 -d bin $(find src -name "*.java")
java -cp bin MAIN_App

---

🖥️ Quick Start (CLI)

ios> help
ios> add-switch S1
ios> add-switch S2
ios> add-link S1:1 S2:1 10
ios> set-priority S1 4096
ios> show topology
ios> show ascii
ios> show ascii mst
ios> ping S1 S2 3 32

Tips:

• configure terminal / end toggles config mode (prompt changes).

• show ascii path S1 S3 highlights shortest path with #.

• Use larger canvas if needed:

  Utils.AsciiTopo.setCanvas(120, 36);

---

🧪 Features (DSA mapping)

Feature	DSA / Algo
CLI command registry	array registry + manual parser
Switch/Link store	parallel arrays (names, priorities, ports, costs, state)
show ascii renderer	Bresenham lines, adaptive circle layout
STP-like MST	Merge Sort + Union-Find (Kruskal local)
ping simulator	custom PriorityQueue (event loop), BFS/Dijkstra path
History	custom Stack (future undo/redo)

---

📦 Project Tree

NetTracer
│   .gitignore
│   LICENSE
│   README.md
│
├── .vscode
│   ├── launch.json
│   └── settings.json
│
├── bin
│   ├── CLI
│   ├── Commands
│   │   ├── General
│   │   └── Switches
│   ├── Engine
│   ├── PDU
│   ├── Topology
│   └── Utils
├── img
└── src
    │   MAIN_App.java
    │
    ├── CLI
    │   ├── CLI_Command.java
    │   ├── CLI_Registry.java
    │   ├── CLI_Shell.java
    │   ├── HistoryManager.java
    │   ├── Stack.java
    │   └── StackNode.java
    │
    ├── Commands
    │   ├── General
    │   │   ├── CMD_Help.java
    │   │   ├── CMD_Hostname.java
    │   │   ├── CMD_Ping.java
    │   │   ├── CMD_Redo.java
    │   │   ├── CMD_Show.java
    │   │   └── CMD_Undo.java
    │   └── Switches
    │       ├── CMD_AddLink.java
    │       ├── CMD_AddSwitch.java
    │       ├── CMD_DelLink.java
    │       ├── CMD_DelSwitch.java
    │       ├── CMD_FailLink.java
    │       ├── CMD_FindSwitch.java
    │       ├── CMD_RecoverLink.java
    │       ├── CMD_RenameSwitch.java
    │       └── CMD_SetPriority.java
    │
    ├── Engine
    │   ├── NetEngine.java
    │   └── NetRouting.java
    │
    ├── PDU
    │   ├── PDU.java
    │   ├── PQNode.java
    │   └── PriorityQueue.java
    │
    ├── Topology
    │   ├── Edge.java
    │   ├── Graph.java
    │   ├── LinkedList.java
    │   └── LLNode.java
    │
    └── Utils
        └── AsciiTopo.java

---

🧑‍💻 Contributors (Group 04)

• I Wayan Girindra Prasasta (indraprasasta) — F1D02410009
• Fauzan Hari Ramdani (fauzanhari) — F1D02410047
• I Nyoman Widiyasa Jayananda (Schryzon) — F1D02410053
• Indira Ramadhani Sabrina (raraww20) — F1D02410057
• Lalu Tirta Putra Tandela (putraturnerr) — F1D02410119
• Salsabila Nailafahdi (naiaero) — F1D02410135
• Diaeddin R. M. Abumattar (hosny27) — F1D02411007

---

📌 Current Status

• ✅ Prototype CLI, Graph, STP (MST), ASCII Renderer, and Ping Event Engine are working.
• ✅ Approved by assistant YNK.
• 🔧 Open for improvements (undo/redo wiring, VLAN views, STP states per-port).

---

📝 Notes

• Save files as UTF-8 to ensure box-drawing characters render correctly.
• The simulator is educational; timing is tick-based (see NetEngine.tick() delay).
• For larger topologies, increase canvas via AsciiTopo.setCanvas(w, h).

---

_{Made with ♥ for learning real networking with real data structures.}