Direct answer

When diagnosing or configuring a VPN connection with routers and smart devices, setup and decisions usually come down to: where the VPN is terminated (router vs. device), which traffic is allowed to go through it, and which network prerequisites must be true (connectivity, routing, DNS behavior, and device/app support). Your troubleshooting path should mirror those decisions: confirm reachability, confirm the tunnel is actually established, then confirm traffic is flowing as expected from the specific device you care about.

How it works

A VPN connection is essentially a protected “tunnel” between a client (router or device) and a VPN endpoint. If you configure the VPN on the router, all eligible devices behind that router will use the router’s VPN tunnel. If you configure it on individual smart devices, each device (or its VPN-capable app) decides whether and how to route traffic.

Key operating conditions include:

  • The device must be able to reach the VPN server over the internet.
  • DNS resolution may occur inside or outside the tunnel depending on settings, so names can resolve even when traffic isn’t flowing correctly.
  • Some smart devices have limited VPN support or only certain apps can use a VPN, so “VPN enabled” may not cover system-wide traffic.

A useful comparison is to treat each choice as a “routing policy” you verify: router-based routing is broad, device-based routing is selective, and both require confirming actual traffic paths.

Practical context

For a user configuring or diagnosing a setup, the most effective approach is to reduce ambiguity:

  1. Identify the VPN termination point you’re using (router or device/app).
  2. Check that the relevant client shows the tunnel as connected, then test whether the specific device’s outbound behavior changes as expected.
  3. If a smart device doesn’t change behavior, try the same tests from another device to confirm whether the issue is router-wide or device-specific.

When smart devices misbehave, common decision points include DNS behavior, app-only VPN usage, firewall/NAT behavior on the router, and whether the device is actually sending traffic through the VPN-capable path.