adding managing horizon back

Author: batamig

.openpublishing.redirection.defender-for-iot.json

@@ -2,7 +2,7 @@
     "redirections": [          
         {
             "source_path_from_root": "/articles/defender-for-iot/organizations/resources-manage-proprietary-protocols.md",
-            "redirect_url": "/azure/defender-for-iot/organizations/concept-supported-protocols.md",
+            "redirect_url": "/azure/defender-for-iot/organizations/how-to-manage-individual-sensors.md#manage-custom-plugins-legacy",
             "redirect_document_id": false
         },
         {

articles/defender-for-iot/organizations/how-to-manage-individual-sensors.md

@@ -1,7 +1,7 @@
 ---
 title: Maintain Defender for IoT OT network sensors from the GUI - Microsoft Defender for IoT
 description: Learn how to perform maintenance activities on individual OT network sensors using the OT sensor console.
-ms.date: 07/04/2023
+ms.date: 12/07/2023
 ms.topic: how-to
 ---
 
@@ -427,6 +427,31 @@ After clearing data on a cloud-connected sensor:
 
 A confirmation message appears that the action was successful. All learned data, allowlists, policies, and configuration settings are cleared from the sensor.
 
+## Manage custom plugins (legacy)
+
+If you've added custom plugins for proprietary protocols using the legacy Horizon support, you can continue to manage them from the sensor console.
+
+**To access your custom plugins**: Sign into your OT sensor console and select **System settings > Network monitoring > Protocols DPI (Horizon Plugins)**.
+
+**To enable or disable plugins**: Select the **Enable/Disable** toggle for each plugin you want to enable or disable.
+
+**To monitor plugin performance**:  Use the data shown on the **Protocols DPI (Horizon Plugins)** page in the sensor console to understand details about your plugin usage. To help locate a specific plugin, use the **Search** box to enter part of all of a plugin name.
+
+The **Protocols DPI (Horizon Plugins)** lists the following data per plugin:
+
+|Column name  |Description |
+|---------|---------|
+|**Plugin**     | Defines the plugin name.        |
+|**Type**     |   The plugin type, including APPLICATION or INFRASTRUCTURE.      |
+|**Time**     |  The time that data was last analyzed using the plugin. The time stamp is updated every five seconds.       |
+|**PPS**     |   The number of packets analyzed per second by the plugin.  |
+|**Bandwidth**     |    The average bandwidth detected by the plugin within the last five seconds.     |
+|**Malforms**     |  The number of malform errors detected in the last five seconds. Malformed validations are used after the protocol has been positively validated. If there's a failure to process the packets based on the protocol, a failure response is returned.       |
+|**Warnings**     | The number of warnings detected, such as when packets match the structure and specifications, but unexpected behavior is detected, based on the plugin warning configuration.        |
+| **Errors** | The number of errors detected in the last five seconds for packets that failed basic protocol validations for the packets that match protocol definitions. |
+
+Horizon log data is available for export in the **Dissection statistics** and **Dissection Logs**, log files. For more information, see [Export troubleshooting logs](how-to-troubleshoot-sensor.md).
+
 ## Next steps
 
 For more information, see: