🖧 Cisco Real Sim

Browser-based Cisco IOS CLI simulator for CCNA / CCNP lab practice

Practice OSPF, ACLs, NAT, DHCP, STP, IPv6, VLANs — without a hardware lab, without Packet Tracer.

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🏛️ Built by Networkers Home

This simulator was built by Networkers Home — India's leading Cisco + cybersecurity training institute (Bengaluru, since 2005). It's the same lab tool used by our students in the CCNA and CCNP Enterprise programs to practice between live lab sessions on real Cisco hardware.

Want hands-on lab access on real Cisco gear? Networkers Home runs 24×7 lab access at the HSR Layout campus with real Cisco/Palo Alto/Fortinet hardware. Book a demo class →

Compare top training institutes: Top 10 CCNA Institutes in Bangalore · Top 10 CCNP Enterprise Institutes · Top 10 CCIE Enterprise India

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✨ Features

• Hierarchical IOS CLI — User EXEC, Privileged EXEC, Global Config, Interface Config modes
• Drag-and-drop topology — place devices, link interfaces, save/load topologies
• Event-driven simulation — ARP resolution, ICMP echo, packet flow visualization
• Konva.js canvas — zoom, pan, real-time packet animation
• Web Workers — non-blocking simulation runs in a separate thread
• No real device emulation — pure logical simulation (lightweight, runs in any browser)

🎯 Who this is for

• CCNA candidates practicing for the 200-301 exam
• CCNP Enterprise candidates drilling on OSPF, BGP, VLAN config
• Networking instructors wanting a free lab tool for classroom use
• Self-learners who can't afford physical Cisco gear

📚 Learn the underlying skills

This simulator teaches you the syntax. To master networking properly — protocols, troubleshooting methodology, real-hardware muscle memory, exam strategy — train with experts:

Goal	Networkers Home program
Pass CCNA 200-301	CCNA course in Bangalore
Pass CCNP Enterprise	CCNP Enterprise course
Become a network engineer	Network Engineering program
Pass CCIE Enterprise lab	CCIE Enterprise course
Online study (anywhere in India)	Online networking courses

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Supported Cisco Commands

User EXEC Mode (>)

• enable - Enter privileged EXEC mode
• help - Show available commands

Privileged EXEC Mode (#)

• disable - Exit to user EXEC mode
• configure terminal - Enter global configuration mode
• show version - Display system version
• show running-config - Display running configuration
• show startup-config - Display startup configuration
• show ip interface brief - Display interface summary
• show interfaces [name] - Display interface details
• show ip route - Display routing table
• show arp - Display ARP table
• show mac address-table - Display MAC address table
• ping <ip> - Ping a destination
• write memory - Save configuration
• copy running-config startup-config - Save configuration
• erase startup-config - Erase startup configuration
• reload - Reload the system

Global Configuration Mode (config)#

• hostname <name> - Set device hostname
• interface <name> - Enter interface configuration mode
• ip route <network> <mask> <nextHop> - Add static route
• no ip route <network> <mask> - Remove static route
• end - Exit to privileged EXEC mode
• exit - Exit to previous mode

Interface Configuration Mode (config-if)#

• ip address <ip> <mask> - Assign IP address
• no ip address - Remove IP address
• shutdown - Administratively shutdown interface
• no shutdown - Enable interface
• description <text> - Set interface description
• no description - Remove interface description
• exit - Exit to global configuration mode

🚀 Quick Start

Prerequisites

• Docker Desktop installed OR Node.js 18+ installed
• Git (optional, for cloning)

Using Docker (Recommended)

docker-compose up -d
open http://localhost:3000

Development Mode

docker-compose --profile dev up -d
open http://localhost:3000

Local Development (Without Docker)

npm install
npm run dev
open http://localhost:3000

Production Build

npm install
npm run build
npm start

🏗️ Architecture

┌─────────────────────────────────────────────────────────────┐
│                        Next.js Frontend                      │
│  ┌──────────────┐  ┌──────────────┐  ┌─────────────────┐   │
│  │   Toolbar    │  │    Canvas    │  │ Properties Panel│   │
│  │   (React)    │  │   (Konva.js) │  │    (React)      │   │
│  └──────────────┘  └──────────────┘  └─────────────────┘   │
├─────────────────────────────────────────────────────────────┤
│                      Zustand Store                           │
│              (State Management & Worker Comms)              │
├─────────────────────────────────────────────────────────────┤
│                    Web Worker Thread                         │
│  ┌──────────────┐  ┌──────────────┐  ┌─────────────────┐   │
│  │   Topology   │  │  Simulation  │  │  CLI Parser/    │   │
│  │    Engine    │  │    Engine    │  │   Executor      │   │
│  └──────────────┘  └──────────────┘  └─────────────────┘   │
└─────────────────────────────────────────────────────────────┘

🧪 Testing

npm test               # Run tests once
npm run test:watch     # Watch mode

🔌 API Endpoints

• GET /api/health - Health check endpoint

🌍 Environment Variables

• NODE_ENV - Environment mode (development/production)
• PORT - Server port (default: 3000)
• NEXT_TELEMETRY_DISABLED - Disable Next.js telemetry (default: 1)

🔧 Troubleshooting

Build Issues

rm -rf .next
taskkill /F /IM node.exe   # Windows
pkill -f node              # macOS/Linux

Docker Issues

• Ensure Docker Desktop is running
• Check port 3000 isn't in use

Windows-Specific

Use WSL2 or PowerShell if you hit path issues.

🤝 Contributing

Pull requests welcome! For major changes, open an issue first to discuss what you'd like to change.

📜 License

MIT — see LICENSE file for details.

🙏 Built With

• Next.js — React framework
• Konva.js — 2D canvas
• Zustand — state management
• xterm.js — terminal emulator
• TypeScript — type safety

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🏛️ Want to learn networking the right way?

Networkers Home — Bengaluru's leading Cisco + cybersecurity training institute since 2005. 20,000+ alumni placed · 800+ hiring partners · 100% placement guarantee.

Book a free demo class · See our placement record · Talk to a counsellor