A direct answer: what a VPN can and can’t do for IoT

Yes, you can use a VPN to help protect IoT devices—mainly by encrypting the network path and reducing direct exposure between your IoT devices and the rest of the internet. A VPN typically moves device traffic into an encrypted “tunnel,” so eavesdroppers on the network path have less visibility.

However, a VPN is not the same thing as “device security.” If an IoT device has weak authentication, outdated firmware, insecure services exposed on your local network, or poor configuration, a VPN cannot automatically fix those issues. In practice, VPN protection is one layer in a broader defense: device hardening, timely updates, strong local access control, and careful firewall rules still matter.

How a VPN helps IoT protection (the core mechanism)

A VPN works by changing where and how traffic is sent. Instead of IoT traffic traveling directly over the underlying network, the traffic is encapsulated and sent through the VPN tunnel, usually terminating at a VPN endpoint.

For IoT protection, the security benefits you can expect from that mechanism are:

  • Encryption in transit: Network traffic carried inside the tunnel is encrypted, helping protect against interception on untrusted networks.
  • Reduced exposure: If the IoT device is reachable only through the VPN path (for example, by design using routing/firewall rules), fewer outsiders can directly target it.
  • Consistent access control: Centralized VPN authentication and routing can make it easier to control who can reach private services.

Important nuance: many IoT devices still communicate with vendor services (for updates, telemetry, remote features). A VPN can’t guarantee that every vendor interaction is fully “safe” just because a VPN is enabled, especially if traffic is allowed or routed in ways you didn’t intend.

Key limitations and exceptions that can change the outcome

The most common reasons VPNs don’t deliver the expected protection for IoT are not cryptography-related—they’re operational.

  1. Device and local network weaknesses remain If a device is compromised or misconfigured, routing traffic through a VPN doesn’t remove the device’s underlying risk. You still need:
  • strong credentials (and avoiding default passwords),
  • firmware updates when available,
  • minimal open ports and services,
  • segmentation or isolation on your local network.

  1. Split routing vs full routing can undermine coverage Depending on your VPN setup, some traffic may go through the VPN while other traffic still uses the normal route. With IoT, it’s easy to assume “VPN on = all IoT traffic is protected,” but routing choices determine what actually happens.

  2. Compatibility and performance trade-offs VPNs can add latency and reduce throughput. Some IoT protocols are sensitive to network timing, and some devices may not behave well with certain VPN configurations. If the VPN breaks connectivity or causes instability, users sometimes “fix” it in insecure ways.

  3. Where the threat is matters A VPN helps with threats on the path between networks. It does not fully address threats that happen:

  • inside your local network (malicious actors already present),
  • at the device itself (malware, insecure services),
  • at endpoints (compromised servers, compromised accounts).

Practical checks to confirm you’re actually protecting IoT traffic

If you want to use a VPN responsibly for IoT, focus on verification, not assumptions.

  • Check routing behavior for the device. Confirm that the specific IPs/domains your IoT device contacts are routed through the VPN endpoint as intended (for example, by observing network paths from the LAN and comparing before/after VPN changes).
  • Verify the device still updates and functions. Ensure firmware updates, remote control features, and normal operations continue after VPN configuration. Breakage often leads to insecure workarounds.
  • Review firewall and access rules. Make sure IoT services are not broadly exposed on your LAN or to the internet. A VPN should reduce exposure, not coexist with overly permissive access.
  • Confirm authentication and account protection. Even with a VPN, use strong credentials and avoid unnecessary accounts with broad privileges.

If you cannot clearly determine which traffic is going through the VPN tunnel, treat the VPN as a partial measure rather than a complete IoT protection strategy.

The bottom line: when VPN-based IoT protection is useful

A VPN can be a useful protection layer for IoT, especially when you need to reach devices securely from outside trusted networks or when you want to reduce direct exposure.

But VPNs are not a substitute for:

  • patching and firmware maintenance,
  • secure device authentication,
  • limiting open ports and services,
  • sane network segmentation and firewall rules.

When in doubt, prioritize what you can verify: routing, access control, and whether the device is actually safe at the point where threats occur.