In the main Network Settings window, click on your ETHERNET connection then write down the IP address.
If you are on a private home network your IP should start 192x.x, or in some cases 172x.x.
In these situations Wi-Fi has the self-assigned IP address and will not connect to the Internet despite the Internet working on other devices.
On the Network Preferences page the Wi-Fi will also show the Self-Assigned IP Address text instead of connected.
I tried various suggested methods for fixing this and none of them worked.
However I managed to fix it in the end without any online help, just some common sense and various stages of trial and error.I've got a Mac Book Air running Mojave and a HUB 3.0. Apple Community Forums As some of them require you to remove or alter files I wouldn't want to link any specific fixes to try as i OS isn't the operating system I'm experienced with. UK based and you will get a speedy reply and resolution to your issue.Thanks, Tom_S I dont know what the issue is - all my Macs "just work" but I would post the question in the Usenet group (yes they are still active! --------------------Services: HD TV on VIP ( Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 Wi Fi,) SH2 in modem mode with Airport Extreme Router.As soon as I turn off their wifi the ethernet goes back to a self-assigned IP address.Any advice would be very much appreciated as I want all of my workstations to be hard wired.A lot of times your Mac is issued a self-assigned IP, which causes the Internet to not work on the machine. Despite the same Wi-Fi network working on other devices, the Mac will simply show no internet connection error and Internet will not work on it. I always go for the Show Networks option as it is easier for me.If you know all your details though, it may be faster to just type them in yourself. If it is a private home network the chances are it will be WPA2 or WEP.So in case it helps anyone else, this is what worked for me.There are two ways to add a network (as you probably know).