Lab: Map Your Home Network

This lab makes the central lesson of the connected-device map real: the cheapest device on your network can set the security of the whole house. You’ll inventory your own network, find the IoT gadgets, and trace how a foothold on one reaches your laptop.

Rules of engagement

Scan only your own home network — the one you own and control. Port-scanning networks you don’t own (a campus, an office, a café) can be illegal and will trip security monitoring. Stick to passive identification; do not attempt to log into other people’s devices.

Setup

On Windows?

This lab is networking-heavy, so use WSL2 (with mirrored networking) or native Nmap for Windows — see Windows Setup. Use ipconfig instead of ip addr to find your IP and gateway; the nmap commands are identical. Avoid Docker here — a container can’t see your real home network.

# macOS
brew install nmap
# Linux
sudo apt install nmap

The exercise

1. Find your network range.

   # macOS
   ipconfig getifaddr en0          # your IP, e.g. 192.168.1.37
   # Linux
   ip addr | grep inet

   Your router is usually .1 (e.g. 192.168.1.1), and your subnet is 192.168.1.0/24.

2. Discover every device (a ping sweep).

   nmap -sn 192.168.1.0/24

   This lists the live hosts without probing them hard. Count them — most people are surprised how many things are on their network.

3. Identify what each device is.

   nmap -sV --top-ports 20 192.168.1.45     # one device at a time

   Open ports and service banners hint at what it is — a printer, a camera, a smart TV, a laptop.

4. Find the smart-home gadgets by name (mDNS/SSDP).

   # macOS
   dns-sd -B _services._dns-sd._udp local.
   # Linux
   avahi-browse -a -t

   IoT devices announce themselves chattily — “Chromecast”, “MyCam”, “ESP_xxxx”. This is the same free reconnaissance you saw over Bluetooth.

5. Spot the weakest link — observe only.

   Look for the device running an old HTTP admin page, Telnet, or an outdated service banner. Do not log in — just note it. That is your most likely entry point (map pin #1: default credentials; pin #6: stale firmware).

6. Trace the pivot.

   Notice that the weak camera/bulb and your laptop and phone are on the same flat network. An attacker who compromises the gadget is now one hop from the valuable machines — map pin #3 and #10, lateral movement.

What you just proved

Reconnaissance of a whole home is trivial, and a network is only as strong as its weakest device. A ₹600 bulb with a default password and your banking phone sharing one network is the real risk.

How it’s defended

• Segmentation → put IoT devices on a separate guest network / VLAN, isolated from your laptop and phone. This single step breaks the pivot.
• Defaults & updates → change default device passwords; keep router and device firmware updated; retire gadgets the vendor has abandoned (map pins #1, #6).
• Least exposure → disable remote admin and unused services on the router.

Debrief

• How many devices did you find — and how many can you actually update?
• Which is your weakest link, and what would isolating it cost you in convenience?
• Re-read pins 3 and 10 on the connected-device map; you’ve now walked the pivot path yourself. Pairs naturally with the Bluetooth lab — two ways the same home gets enumerated.