Set up Internet Connection Sharing for Windows 7 and iPhone X to share internet hotspot with Asus AC2900 RT-AC86U router

Solution 1:

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":

Solution 2:

After running as a fixed IP for some time, things like iPad and my PS3 consoles had issues connecting and obtaining IP addresses. It turned out that a firmware update plus factory reset allowed me to create a new wireless connection. I found I could connect to my own router via a 2nd wireless connection (as well as Ethernet) that allowed the http://router.asus.com/index.asp configuration options:

So in the end the connection was a default wireless router mode with default dynamic IPv4 and IPv6 and external clients can connect and share internet.