Securing Your Smart Home: Step-by-Step Network Segmentation

Technological convenience has shaped our daily lives to such an extent that smart homes have become the pinnacle of modern living.

Intelligent lighting systems, smart thermostats, and sophisticated home security solutions have all played a magistral role in helping our homes become interconnected. In fact, these advancements have created an ecosystem that allows us to become connected to our homes.

Although the convenience of controlling much about everything in your home remotely sounds appealing, there are some drawbacks that smart home enthusiasts rarely address: cyber threats.

What is network segmentation?

Every smart device added to your home network expands the attack surface a threat actor could exploit for malicious purposes. In other words, each smart device creates potential entry points for cyber threats.

That’s where network segmentation comes into play.

One of the most effective strategies to bolster your smart home’s security against various cyberthreats, network segmentation involves dividing your home network into smaller, isolated segments, commonly referred to as “subnetworks.”

Understanding network segmentation

Network segmentation enables you to create isolated segments within your network, each acting independently as a distinct compartment.

Devices within any given segment can communicate freely with other devices in the same compartment. However, interactions between segments are either strictly controlled or prohibited, depending on the end user’s security preferences.

Obviously, cutting communication completely between segments involves a tighter level of security, but it may come with drawbacks as far as convenience goes.

Either way, segmenting your network can dramatically reduce the risk of a single compromised device affecting your entire home network.

Why segment your smart home network?

Smart home devices vary widely in terms of security, as some may be more susceptible to digital intrusions or expose users to more severe attacks than others.

Paradoxically, devices that are typically high risk, like security cameras, IoT sensors or smart TVs, have weaker built-in protections, which makes them easy targets for threat actors.

Segmenting these devices, for instance, helps keep them away from critical systems, such as smartphones, personal computers, and storage devices. By doing so, you can ensure the integrity of your network and protect your sensitive data.

Step-by-step guide to network segmentation

Our guide aims to provide detailed, step-by-step instructions to implement robust segmentation to safeguard your smart home ecosystem.

1. Inventory your devices

The first step is to identify and catalog all devices connected to your home network. If you don’t know where to start, use the list of common categories below as a starting point:

Computers, laptops, tablets and smartphones (sensitive personal data)
Smart home controllers and hubs
Security cameras and smart locks
Smart TVs and entertainment systems
IoT sensors and appliances (refrigerators, thermostats)

Understanding the extent of your smart home network ecosystem helps you improve your network segmentation efficacy.

2. Determine network segments

Decide how to divide your network. Most people segment their home network based on risk profiles, others base their segmentation on device function, and others take a hybrid approach.

Below, you will find a common way to segment your smart home network:

Main network: personal devices (desktop computers, laptops, tablets, smartphones)
Guest network: a network created specifically for visitors’ devices
IoT network: This category should fit smart home devices, such as smart TVs, appliances (washing machines, refrigerators, ovens, AC units), sensors, hubs, thermostats, and other daily-use internet-enabled devices in your household
Security network: This segment should include everything security-related in your smart home ecosystem, including security cameras, alarms, DVRs, NVRs, smart locks, and sensors

3. Use suitable hardware

The importance of using suitable hardware for network segmentation cannot be overstated. You should generally aim for routers or firewalls that support network segmentation to avoid compatibility issues and spending time looking for workarounds.

Routers with VLAN (Virtual Local Area Network) capabilities, for instance, or advanced home routers that can create and manage multiple, separate SSIDs (wireless networks) are ideal.

Try to opt for reputable brands, such as Netgear. While many consumer-grade routers claim advanced functionality, not all support true VLAN segmentation, a crucial feature for creating secure, isolated subnetworks.

Furthermore, make sure your router or firewall firmware is always up to date to protect against known vulnerabilities.

4. Set up separate networks (VLAN)

Use your router’s administrative interface to create separate Virtual LANs for each desired segment. This step varies depending on your router’s manufacturer, but the process should be straightforward, resembling these general steps:

Access your router’s administrative interface using your admin username and password
Navigate to your router’s network settings (look for Virtual LAN or VLAN)
Define new VLANs, assigning unique identifiers to each one
Name VLANs according to their usage (i.e., “IoT Devices,” “Guest Network,” “Personal Devices”)

5. Assign devices to created network segments

After creating secure, isolated segments on your network, it’s time to connect devices to their VLANs. You can do that either physically, via Ethernet ports, or wirelessly, by assigning separate SSIDs for each VLAN.

Remember, you want to assign your personal devices to your secure, primary VLAN, IoT, security and entertainment devices to isolated VLANs, and also have a guest wireless network for visitors.

6. Enforce firewall rules

Although your devices should now be separated into individual segments on your home network, technically, they can still communicate with each other. To prevent or regulate these inter-segment communications, you need firewall rules.

These rules are designed to control how and whether traffic flows between segments. As before, firewall rule management depends on what provider you use. These general rules can help you create a solid firewall rule plan:

Restrict IoT devices from initiating connections to your primary network
Prohibit guest network devices from accessing internal resources on your network
Restrict security device VLANs from communicating with any other network

Note that these rules can and should change and adapt to each use case. If you're stuck, use them as a starting point and configure them to fit your smart home ecosystem as needed.

7. Test network segmentation

After adding the devices to their corresponding isolated segment on your network, the next step is to test the connection and verify that the segmentation is effective.

Confirm that each device is on the correct VLAN. Modern routers provide an administrative interface that allows you to check which segment each device connects to. For devices with screens, such as computers, smartphones, and tablets, you can simply check which network they’re connected to if you have assigned a separate SSID for each VLAN.

Once you have established that each device is connected to its corresponding segment, test the firewall rules by attempting to connect from a device on one segment to another, ensuring that unwanted access is effectively blocked.

Last but not least, run port scans on isolated segments to check for leaks or accidental openings.

Advanced tips for enhanced security

While network segmentation is a great way to secure your smart home ecosystem, you can take a few additional steps to bolster your network’s security even further.

MAC address filtering: Implementing MAC address filtering restricts network access by allowing only pre-approved devices.
Regular security audits: Periodic security audits of your network segments and firewall rules allow you to discover vulnerabilities or misconfigurations before they cause harm.
Intrusion detection: Consider integrating additional security layers, such as Intrusion Detection System (IDS), which actively monitors network traffic and alerts you immediately to suspicious activities or potential breaches.

Common challenges and solutions

Network segmentation isn’t always seamless and could raise various issues. Two of the most common challenges network segmentation adopters face are:

Compatibility issues: Some IoT devices may struggle to recognize VLAN configurations. In such cases, simplified segmentation using separate physical routers or wireless access points can be effective.
Configuration complexity: Detailed firewall configuration can look intimidating at first. Reputable manufacturers typically provide comprehensive documentation to help set up advanced network segmentation features. Alternatively, you could seek guidance from online community forums.

Network segmentation best practices

Consistent adherence to best practices ensures long-term security success. Although configuring and managing multiple devices can feel daunting, practicing good cyber hygiene definitely pays off in the long run. Best practices in network segmentation include:

Regularly update device firmware and security patches
Avoid default passwords or ones that can be easily cracked on your network equipment
Keep your network simple enough to manage, monitor, and troubleshoot effectively but thorough enough to isolate vulnerabilities and cyber attacks

Conclusion

Implementing network segmentation in your smart home significantly elevates your cybersecurity posture, protecting your privacy and ensuring your home remains secure against cyber threats.

By segregating networks and employing strategic firewall rules, you build robust defenses that prevent breaches from spreading, securing both your digital and physical spaces.

Frequently Asked Questions about Network Segmentation

What is network segmentation?

Network segmentation divides your home network into separate, isolated subnetworks, enhancing security by restricting communication between devices.

Does network segmentation slow down my internet?

Properly implemented segmentation won't noticeably slow your network and instead will optimize performance by managing traffic more efficiently.

Can all routers support segmentation?

Not all routers support advanced segmentation. Verify your router’s specifications or consider upgrading to one with VLAN or multiple SSID capabilities.