• What This Project Is
• Why Smart Home Networking Matters
• Network Design
• Network Topology Diagram
• Key Networking Concepts
• How to Open the Simulation
• What to Explore
• Security Considerations
• Tools Used
• Author
• License

A smart home network I designed and simulated in Cisco Packet Tracer. The setup includes a gateway router, wireless access point, and several IoT devices (smart lights, thermostat, cameras, door lock) all connected and configured with proper IP addressing and wireless settings. Everything runs on a single simulation file so you can open it and poke around.

Simulation file: MY PACKET TRACER - Copy.pkt

• Default credentials -- Many IoT devices ship with factory-set passwords that are publicly documented and rarely changed.
• Unencrypted traffic -- Low-cost devices frequently transmit data in plaintext, exposing usage patterns and camera feeds.
• Lateral movement -- A compromised IoT device on a flat network can be a pivot point to personal computers and other high-value targets.
• Firmware neglect -- Consumer IoT devices often lack automatic updates, leaving known vulnerabilities unpatched for months or years.
• Weak network segmentation -- Most home networks place all devices on a single subnet with no isolation between trusted and untrusted endpoints.

The simulation models a typical residential smart home with the following network components:

Each device is assigned an IP address via DHCP or static configuration and communicates over the shared home network infrastructure.

                        +-----------------+
                        |    INTERNET     |
                        |   (ISP Cloud)   |
                        +--------+--------+
                                 |
                                 | WAN
                                 |
                        +--------+--------+
                        |  GATEWAY ROUTER |
                        |  (DHCP, NAT,    |
                        |   Firewall)     |
                        +--------+--------+
                                 |
                                 | LAN
                                 |
                   +-------------+-------------+
                   |                           |
          +--------+--------+        +---------+---------+
          |   HOME SERVER   |        |  WIRELESS ACCESS  |
          |   / DESKTOP PC  |        |      POINT        |
          +-----------------+        +---------+---------+
                                               |
                                               | Wi-Fi
                                               |
                +-----+-----+-----+-----+-----+-----+
                |     |     |     |     |     |      |
               [A]   [B]   [C]   [D]   [E]   [F]   [G]

Legend:

Note: The exact topology may vary within the .pkt file. Open the simulation to explore the full layout and device interconnections.

Networking concepts covered:

• DHCP (Dynamic Host Configuration Protocol) -- The gateway router assigns IP addresses dynamically to connected devices, handling address allocation without manual intervention.
• Wireless Configuration (802.11) -- The access point is configured with an SSID, security mode, and authentication parameters.
• IoT Device Connectivity -- Each smart device is registered on the network and communicates over TCP/IP.
• IP Addressing and Subnetting -- Devices are organized within a defined IP address range on a residential subnet.
• Network Segmentation Concepts -- The design highlights where segmentation boundaries should exist between IoT and personal computing devices.
• Device Registration and Management -- Smart devices are added to the network and configured to interact with one another.

Cisco Packet Tracer is available for free through the Cisco Networking Academy.

1. Visit Cisco Networking Academy and create a free account.
2. Enroll in the "Getting Started with Cisco Packet Tracer" course (free).
3. Download Cisco Packet Tracer for your operating system (Windows, macOS, or Linux).
4. Install and launch the application.

System Requirements: Cisco Packet Tracer runs on Windows 10/11, macOS 10.14+, and Ubuntu 20.04+. A minimum of 4 GB RAM is recommended.

1. Clone or download this repository:

   git clone https://github.com/your-username/Cisco-packet-tracer.git

2. Open Cisco Packet Tracer.
3. Go to File > Open and navigate to the downloaded repository folder.
4. Select MY PACKET TRACER - Copy.pkt and click Open.

Once the file loads, you will see the full smart home network topology displayed in the workspace. You can zoom in and out, click on individual devices, and interact with the simulation in real time.

Click on any device in the topology to open its configuration panel. Examine:

• IP address assignments (static vs. DHCP)
• Default gateway settings
• Wireless interface parameters (SSID, channel, security mode)

Use the built-in tools to verify network connectivity:

1. Open the Command Prompt on any PC or server device.
2. Run ping <target IP> to test reachability between devices.
3. Use ipconfig (on PCs) to view current network configuration.
4. Try pinging from an IoT device to the gateway to confirm registration.

Navigate to the gateway router and examine the DHCP pool:

• What IP range is assigned to devices?
• Which devices received addresses via DHCP?
• Are any devices statically configured?

Click on the wireless access point to review:

• SSID name and broadcast settings
• Security protocol (WPA2-PSK, WPA3, or open)
• Connected client list

Interact with smart home devices to observe:

• How IoT devices communicate with the home server
• Data flow patterns between sensors and controllers
• Device state changes (e.g., turning a light on/off)

The most effective defense for a smart home network is proper segmentation. IoT devices should be isolated from personal computing devices on a separate VLAN or subnet. A compromised smart bulb shouldn't be a stepping stone to a laptop with sensitive data.

Recommended architecture:

• VLAN 10 -- Trusted Devices: PCs, laptops, smartphones
• VLAN 20 -- IoT Devices: Smart lights, thermostats, cameras, locks
• VLAN 30 -- Guest Network: Visitor devices with internet-only access

Every device on the network should have its default credentials changed immediately upon deployment. This includes:

• Router admin panel username and password
• Wireless access point management credentials
• IoT device companion app accounts
• Any web-based management interfaces

IoT devices should be checked regularly for firmware updates. Many manufacturers release patches for critical vulnerabilities, but devices rarely update themselves. Establishing a maintenance schedule is essential.

Monitoring network traffic from IoT devices can reveal anomalous behavior such as:

• Unexpected outbound connections to unknown IP addresses
• High-volume data transfers from devices that should produce minimal traffic
• DNS queries to suspicious or newly registered domains

Where possible, ensure that communication between IoT devices and their cloud services uses TLS/HTTPS. Devices that transmit data in cleartext should be flagged and either replaced or placed behind additional network controls.

Chioma Iroka Computer Science Graduate | Cybersecurity Focus

• GitHub: github.com/ChiomaIroka

This project is released under the MIT License.