Two resolutions. First being easier, second being overly complex that even I don't want to approach as it requires programming.
Resolution One: You use a hostednetwork if your wireless adapter is capable. (Usually they are capable.)
1.) Open an elevated command prompt. Win+X and choose CMD (Admin) OR type in "cmd" or "command prompt" into Windows Search by typing into Start Menu and then right click "Command Prompt" and select "Run As Administrator"
2.) Check if your system is capable run this command: netsh wlan show drivers. Scroll down to Hosted network supported. If it saysYes you are in luck; if No there is no easy alternative and don't continue.
3.) Run the following command to allow and set up your hostednetwork but look below first.
netsh wlan set hostednetwork mode=allow ssid=%ssid% key=%pass% keyUsage=persistent
Replace %ssid% with your Wifi or "Hotspot" Name or SSID. E.g. ssid=MyGreatHotspot. Replace %pass% with your Wifi or "Hotspot" Password. It must be 8 characters long at a minimum. E.g. key=strongPasswordsAreWEAK.
4.) After that run the command, netsh wlan start hostednetwork, to start the "Hotspot" broadcast. Right now you can play without internet connection after all devices connect. Remember to check IP addresses of all your individual devices in order to connect to each other. The hotspot's IP Address usually is "192.168.137.1".
If you want to share your internet connection or for further reference, continue on:
5.) Open Run (Win + R) or by searching for Run and enter in ncpa.cpl, then press Enter. A new adapter has shown in the screen it should say something along the lines of "Microsoft Hosted Network Virtual Adapter". (Optional if you're OCD, rename that one if its says "L.A.N Connection* 15" or rather to like "Hotspot"). Right click the Internet Connect Source you want to share internet from and choose "Properties." Go to the "Sharing" Tab and checkmark or toggle on "Allow other network users to connect through this computer's Internet Connection." Apply, OK to save changes.
6.) You should be all set! :)
If you want to stop the hostednetwork, in an elevated command prompt you run the command: netsh wlan stop hostednetwork
Resolution Two: This is taken from this post from user Linard Arquit
In case writing your own application is a possibility, have
a look at the WiFi Direct API, which offers a legacy mode. Enabling
the legacy mode will create a SoftAP with the specified SSID and
password. However, specifying no password doesn't seem to be
supported.
Have a look at the IoTOnboarding sample to see the legacy mode in
action (and to have a better 'documentation' than what Microsoft
officially provides):
IotOnboarding/IoTOnboardingService/OnboardingAccessPoint.cs
Why not use ICS (Internet Connection Sharing) instead of a bridged connection? It works way better, especially with that kind of setup.
Right-click on your Local Area Network 3 icon, choose Properties, go to the Sharing tab, and check the Share this connection box (the other option isn't necessary). You'll be good to go in a matter of seconds, because Windows will know you want to share this iPhone connection with the other available network adapter, namely your Ethernet port.
Best Answer
This question and this question helped. I set up a fixed IP address for my Asus Router.
However, I could not set up a fixed IP address for my iPhone so left it as automatic.
This answer then got everything to work. The Router has to be set up as an ACCESS POINT.
It does not make the Router show as "Internet" because the router is not directly connected to the internet. The Router (renamed from Local Area Connection) still shows as "No Internet Access":