Microsoft Defender for IoT
GeneralConfigure reverse DNS lookup for OT active monitoring - Microsoft Defender for IoT
In brief
Updated the page metadata, clarified the OT sensor activation prerequisite link text, and renamed the final section from “Next steps” to “Related content.”
What Defender admins need to know
Administrators can use the clearer prerequisite wording and updated related-content section when configuring reverse DNS lookup.
Summaries are generated from the documentation change itself.
Documentation change
View on Microsoft LearnThe comparison below shows only the changed extract. Use the full-page view for complete context.
Configure DNS servers for reverse lookup resolution for OT monitoring
Before configuring reverse DNS lookup, make sure you have:
An OT network sensor with OT sensor software installed and configured and activated your OT sensor.
Access to your OT network sensor as an Admin user. For more information, see On-premises users and roles for OT monitoring with Defender for IoT.
Completed the prerequisites outlined in Configure active monitoring for OT networks, and confirmed that active monitoring is right for your network.
Define DNS servers
On your OT sensor console, select System settings > Network monitoring and under Active Discovery, select Reverse DNS Lookup.
In the DNS reverse lookup test for server dialog, enter an address in the Lookup Address and then select Test.
Next stepsRelated content
After configuring reverse DNS lookup, you can review resolved host names in:
@@ -1,10 +1,10 @@ --- title: Configure reverse DNS lookup for OT active monitoring - Microsoft Defender for IoT description: This article describes how to configure reverse DNS lookup for active monitoring with Microsoft Defender for IoT.-ms.date: 06/12/2026+ms.date: 07/03/2026 ms.topic: how-to ai-usage: ai-assisted-ms.custom: msecd-doc-authoring-1014+ms.custom: msecd-doc-authoring-1016 --- # Configure DNS servers for reverse lookup resolution for OT monitoring@@ -19,13 +19,12 @@ All CIDR formats are supported. Before configuring reverse DNS lookup, make sure you have: -- An OT network sensor with [OT sensor software installed](ot-deploy/install-software-ot-sensor.md) and [configured and activated](ot-deploy/activate-deploy-sensor.md).+- An OT network sensor with [OT sensor software installed](ot-deploy/install-software-ot-sensor.md) and [configured and activated your OT sensor](ot-deploy/activate-deploy-sensor.md). - Access to your OT network sensor as an **Admin** user. For more information, see [On-premises users and roles for OT monitoring with Defender for IoT](roles-on-premises.md). - Completed the prerequisites outlined in [Configure active monitoring for OT networks](configure-active-monitoring.md), and confirmed that active monitoring is right for your network. - ## Define DNS servers 1. On your OT sensor console, select **System settings** > **Network monitoring** and under **Active Discovery**, select **Reverse DNS Lookup**.@@ -55,9 +54,7 @@ Use a test device to verify that the reverse DNS lookup schedule, DNS server, an 1. In the **DNS reverse lookup test for server** dialog, enter an address in the **Lookup Address** and then select **Test**. -## Next steps--After configuring reverse DNS lookup, you can review resolved host names in:+## Related content - [View your device inventory from a sensor console](how-to-investigate-sensor-detections-in-a-device-inventory.md) - [View your device inventory from the Azure portal](how-to-manage-device-inventory-for-organizations.md)