What is the best approach to prevent a compromised IoT device from maliciously accessing data and devices on a local network?

What is the best approach to prevent a compromised IoT device from maliciously accessing data and devices on a local network?

• A. Disable all IoT devices
• B. Use VLAN with restricted interconnects
• C. Keep IoT devices on the main network
• D. Place all IoT devices that have access to the Internet on an isolated network

Answer: (D)

Isolating devices that have Internet access on their own network segment is the safest way to limit what a compromised IoT device can reach. When IoT devices live on a separate network, the amount of trust assigned to them is minimized, and their ability to communicate with other devices and data on the main LAN is tightly controlled by firewalls, access control lists, and strict routing rules. Even if one device is taken over, the attacker faces fewer avenues to move laterally to servers, databases, or other systems that matter, because there is no direct path from that isolated network to the internal network. This approach creates a clear boundary: IoT devices can still access needed Internet services and updates, but their connections to the core network are restricted by the firewall and routing policies. The separation reduces the blast radius and makes monitoring and containment easier. Disabling all IoT devices isn’t practical and defeats the purpose of using them. Keeping IoT devices on the main network keeps them within the same trust domain, increasing the risk that a compromised device could access sensitive resources. Using a VLAN with restricted interconnects can help, but it relies on correct configuration and ongoing maintenance; a dedicated isolated network provides a stronger, more predictable barrier against uncontrolled access.

Isolating devices that have Internet access on their own network segment is the safest way to limit what a compromised IoT device can reach. When IoT devices live on a separate network, the amount of trust assigned to them is minimized, and their ability to communicate with other devices and data on the main LAN is tightly controlled by firewalls, access control lists, and strict routing rules. Even if one device is taken over, the attacker faces fewer avenues to move laterally to servers, databases, or other systems that matter, because there is no direct path from that isolated network to the internal network.

This approach creates a clear boundary: IoT devices can still access needed Internet services and updates, but their connections to the core network are restricted by the firewall and routing policies. The separation reduces the blast radius and makes monitoring and containment easier.

Disabling all IoT devices isn’t practical and defeats the purpose of using them. Keeping IoT devices on the main network keeps them within the same trust domain, increasing the risk that a compromised device could access sensitive resources. Using a VLAN with restricted interconnects can help, but it relies on correct configuration and ongoing maintenance; a dedicated isolated network provides a stronger, more predictable barrier against uncontrolled access.