Add firewall allow note - closes #117

Author: jasonacox

README.md

@@ -52,7 +52,7 @@ Controlling and monitoring Tuya devices on your network requires the following:
 
 ### Network Scanner
 
-TinyTuya has a built in network scanner that can be used to find Tuya Devices on your local network. It will show *Address*, *Device ID* and *Version* for each device.  
+TinyTuya has a built in network scanner that can be used to find Tuya Devices on your local network. It will show *Address*, *Device ID* and *Version* for each device. Your LAN and firewall will need to allow UDP (6666, 6667 and 7000) and TCP (6668) traffic.
 
 ```bash
 python -m tinytuya scan
@@ -97,7 +97,7 @@ TinyTuya has a built-in setup Wizard that uses the Tuya IoT Cloud Platform to ge
     * It will also ask for a sample *Device ID*.  Use one from step 2 above or found in the Device List on your Tuya IoT project.
     * The **Wizard** will poll the Tuya IoT Cloud Platform and print a JSON list of all your registered devices with the "name", "id" and "key" of your registered device(s). The "key"s in this list are the Devices' *Local_Key* you will use to access your device. 
     * In addition to displaying the list of devices, **Wizard** will create a local file `devices.json` that TinyTuya will use to provide additional details for scan results from `tinytuya.deviceScan()` or when running `python -m tinytuya scan`. The wizard also creates a local file `tuya-raw.json` that contains the entire payload from Tuya Cloud.
-    * The **Wizard** will ask if you want to poll all the devices. If you do, it will display the status of all devices on record and create a `snapshot.json` file with these results.
+    * The **Wizard** will ask if you want to poll all the devices. If you do, it will display the status of all devices on record and create a `snapshot.json` file with these results. Make sure your LAN and firewall permit UDP (6666, 6667 and 7000) and TCP (6668) traffic.
 
 Notes:
 * If you ever reset or re-pair your smart devices, the *Local_Key* will be reset and you will need to repeat the steps above.