Modern, lightweight network labs using Containerlab and FRR routing

Learn OSPF, BGP, and Linux networking with hands-on containerized labs. No VMs required!

Traditional network labs (GNS3, EVE-NG) require heavy virtual machines and complex setup. These containerized labs offer:

• ✅ 75% less memory - ~50MB per router vs 1GB+ for VM-based labs
• ✅ 96% faster startup - 30 seconds vs 10+ minutes
• ✅ Zero configuration - One-click deployment with VS Code devcontainers
• ✅ Modern approach - Docker containers, not VMs

Learn OSPF fundamentals with a simple 3-router topology. Perfect for understanding OSPF operation, DR/BDR election, and basic troubleshooting.

→ Start OSPF Lab

Understand external BGP with a 4-router, 3-AS topology. Learn BGP neighbor establishment, route propagation, and AS-path manipulation.

→ Start BGP Lab

Explore how containerlab uses Linux network namespaces to create isolated network environments. Understand the foundation of container networking.

→ Start Linux Namespaces Lab

All labs include SSH access with auto-login to router CLI - just like real Cisco/Juniper routers!

Credentials:

• Username: admin
• Password: cisco

Access methods:

1. VS Code Extension (easiest) - Right-click container → SSH
2. Port mapping - ssh -p 2221 admin@localhost
3. Container name - ssh admin@clab-ospf-basics-r1

You land directly at the router CLI:

$ ssh -p 2221 admin@localhost Password: cisco r1# ← Router CLI (not bash shell!) r1# show ip ospf neighbor r1# show ip route 

See SSH-SETUP-COMPLETE.md for complete documentation.

# Install containerlab (Linux/Mac) bash -c "$(curl -sL https://get.containerlab.dev)" # Verify installation containerlab version

# Clone this repo git clone https://github.com/ciscoittech/containerlab-free-labs.git cd containerlab-free-labs # Build frr-ssh image (first time only) ./build-frr-ssh.sh # Option 1: Run in VS Code with devcontainer (recommended) cd ospf-basics code . # Click "Reopen in Container" # Option 2: Run locally cd ospf-basics sudo containerlab deploy -t topology.clab.yml # Access routers via SSH (recommended) ssh -p 2221 admin@localhost # OSPF r1 # Password: cisco # Lands directly at router CLI: r1# # Alternative: Docker exec docker exec -it clab-ospf-basics-r1 vtysh # Cleanup sudo containerlab destroy -t topology.clab.yml

1. Start here: Linux Network Namespaces (understand the foundation)
2. OSPF Basics: Learn link-state routing protocols
3. BGP eBGP Basics: Understand internet routing fundamentals

Contributions are welcome! See CONTRIBUTING.md for guidelines.

Quick start:

1. Fork this repo
2. Create a feature branch (git checkout -b feature/new-lab)
3. Test in devcontainer (./scripts/validate.sh)
4. Submit a PR

Want to add a lab? Check our lab template

• Containerlab Documentation
• FRRouting Documentation
• Network Automation Community

MIT License - Use these labs for learning, teaching, or building your own projects!

Note: These labs use FRR (Free Range Routing) which provides Cisco-like syntax for BGP, OSPF, IS-IS, and more. Perfect for CCNA/CCNP lab practice without expensive hardware!