No, Custom DNS settings do not take effect immediately. Devices with an active session continue to use the previous DNS configuration until they fully disconnect and reconnect to the network. Existing network connections continue to use the existing DNS settings.
Requirements
For a device to receive the new DNS settings, make sure the following conditions are met:
- The IoT SIM belongs to the group where Custom DNS is enabled. Custom DNS settings only apply to IoT SIMs in that group. See the Configuration section for details.
- The device is configured to obtain DNS settings automatically.
If a device has manually configured DNS servers, those settings may override Custom DNS. See Custom DNS for details.
How to Apply the New Settings
The device must establish a new session to receive the updated DNS settings. You can do this from the device side by:
- Rebooting the device
- Disabling and re-enabling the cellular network interface
Alternatively, you can end the existing session remotely:
- User Console: Use the Delete session action.
-
API: Use the deleteSimSession API (
POST /sims/{sim_id}/delete_session).
After the session ends, the device automatically receives the updated DNS settings when it reconnects.