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Lab Manual
This lab series takes you from L2 to L3, progressively understanding how networks work.
Lab List
| Lab | Topic | Learning Content | Time |
|---|---|---|---|
| Lab 1 | Single Subnet Experiment | L2 Forwarding, ARP, IP Configuration, Packet Capture | 30 minutes |
| Lab 2 | VLAN Experiment | VLAN Isolation, Access Port, 802.1Q | 30 minutes |
| Lab 3 | Router Connecting Multiple Subnets | L3 Forwarding, Gateway, Routing Table | 30 minutes |
Environment Requirements
- GNS3 installed and configured
- Docker installed (for Linux containers)
Components Used
This tutorial uses Linux as network devices:
| Component | Purpose | Description |
|---|---|---|
| Linux | Switch / Router | Uses ip command and bridge tools |
| VPCS | End Hosts | GNS3 built-in lightweight host simulation |
| Wireshark | Packet Analysis | GNS3 built-in integration |
Why Use Linux?
- ✅ Free and Open Source - No licenses or registration required
- ✅ Real Environment - Same network stack as actual servers/devices
- ✅ Practical Skills - Commands learned can be directly applied at work
- ✅ Lightweight Resources - Smaller and faster than commercial NOS images
Network Fundamentals Review
L2 vs L3
| Layer | Name | Address | Device | Scope |
|---|---|---|---|---|
| L2 | Data Link | MAC | Switch | Same Segment (LAN) |
| L3 | Network | IP | Router | Cross Segment (WAN) |
Important Terms
| Term | Description |
|---|---|
| Bridge | Linux software switch |
| VLAN | Virtual LAN, logical isolation |
| Gateway | Default gateway, exit point for cross-segment traffic |
| ARP | IP → MAC translation protocol |
| TTL | Time To Live, prevents infinite packet loops |
Start Labs
Ready? Let's begin with Lab 1: Single Subnet Experiment!