added MQTT prereq for everything but routing

Author: JimacoMS3

articles/iot-hub/tutorial-connectivity.md

@@ -48,6 +48,8 @@ node --version
 
 Download the sample device simulator Node.js project from https://github.com/Azure-Samples/azure-iot-samples-node/archive/master.zip and extract the ZIP archive.
 
+Make sure that port 8883 is open in your firewall. The sample in this tutorial uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](iot-hub-mqtt-support.md#connecting-to-iot-hub).
+
 ## Create an IoT hub
 
 If you created a free or standard tier IoT hub in a previous quickstart or tutorial, you can skip this step.

articles/iot-hub/tutorial-device-twins.md

@@ -47,6 +47,8 @@ node --version
 
 Download the sample Node.js project from https://github.com/Azure-Samples/azure-iot-samples-node/archive/master.zip and extract the ZIP archive.
 
+Make sure that port 8883 is open in your firewall. The sample in this tutorial uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](iot-hub-mqtt-support.md#connecting-to-iot-hub).
+
 ## Set up Azure resources
 
 To complete this tutorial, your Azure subscription must contain an IoT hub with a device added to the device identity registry. The entry in the device identity registry enables the simulated device you run in this tutorial to connect to your hub.

articles/iot-hub/tutorial-firmware-update.md

@@ -47,6 +47,8 @@ node --version
 
 Download the sample Node.js project from https://github.com/Azure-Samples/azure-iot-samples-node/archive/master.zip and extract the ZIP archive.
 
+Make sure that port 8883 is open in your firewall. The sample in this tutorial uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](iot-hub-mqtt-support.md#connecting-to-iot-hub).
+
 ## Set up Azure resources
 
 To complete this tutorial, your Azure subscription must have an IoT hub with a device added to the device identity registry. The entry in the device identity registry enables the simulated device you run in this tutorial to connect to your hub.

articles/iot-hub/tutorial-manual-failover.md

@@ -27,7 +27,9 @@ In this tutorial, you perform the following tasks:
 
 ## Prerequisites
 
-- An Azure subscription. If you don't have an Azure subscription, create a [free account](https://azure.microsoft.com/free/?WT.mc_id=A261C142F) before you begin.
+* An Azure subscription. If you don't have an Azure subscription, create a [free account](https://azure.microsoft.com/free/?WT.mc_id=A261C142F) before you begin.
+
+* Make sure that port 8883 is open in your firewall. The sample in this tutorial uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](iot-hub-mqtt-support.md#connecting-to-iot-hub).
 
 ## Create an IoT hub
 

articles/iot-hub/tutorial-message-enrichments.md

@@ -35,6 +35,9 @@ Here are the tasks you perform to complete this tutorial:
 * You must have an Azure subscription. If you don't have an Azure subscription, create a [free account](https://azure.microsoft.com/free/?WT.mc_id=A261C142F) before you begin.
 * Install [Visual Studio](https://www.visualstudio.com/).
 
+* Make sure that port 8883 is open in your firewall. The sample in this tutorial uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](iot-hub-mqtt-support.md#connecting-to-iot-hub).
+
+
 [!INCLUDE [cloud-shell-try-it.md](../../includes/cloud-shell-try-it.md)]
 
 ## Retrieve the IoT C# samples repository

articles/iot-hub/tutorial-use-metrics-and-diags.md

@@ -38,6 +38,9 @@ In this tutorial, you perform the following tasks:
 
 - An email account capable of receiving mail.
 
+- Make sure that port 8883 is open in your firewall. The sample in this tutorial uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](iot-hub-mqtt-support.md#connecting-to-iot-hub).
+
+
 [!INCLUDE [cloud-shell-try-it.md](../../includes/cloud-shell-try-it.md)]
 
 ## Set up resources