Internet connection sharing (ICS) of wifi adapter to ethernet adapter does not allow ethernet to see the internet

Winver 2262.290

I connect to the internet via my wifi adapter on my Windows 11 PC and I wanted to then use the PC to connect a Raspberry PI4 via Ethernet so that the RPI4 could access the internet. I enabled ICS on the wifi adapter and all was working a few weeks ago. I then connected the RPI4 to the PC today and I find the Ethernet adapter shows 'no internet'. And the RPI4 shows it's on a network but it has no internet access.

I can't seem to find anything on the internet about a similar issue. I've removed the ethernet device and rebooted. And done a network reset, etc. but always the same result. The wifi adapter shows it's sharing and the ethernet adapter reports no internet. FWIW - when I look at the details of the Ethernet adapter, its default IP4 settings are completely different to my home network and wifi adapter's settings. I don't know if this matters or not? Again, I've not found anything on the internet about setting the IP4 settings of the Ethernet adapter when using ICS of the wifi adapter.

On the Windows 11 PC, had you inspected the status of the Internet Connection Sharing (ICS) Service in services.msc console snap-in? Is the service Running? And what is the Startup Type (default Manual)?

iko22 said:

On the Windows 11 PC, had you inspected the status of the Internet Connection Sharing (ICS) Service in services.msc console snap-in? Is the service Running? And what is the Startup Type (default Manual)?

Click to expand...

The service is running and I've set it to start automatically on boot. In the control panel under the section for the network adapters the WiFi adapter also shows as "sharing" and connected to my WiFi router SSID.

On the Windows 11 PC, you could try disabling then re-enabling the ICS service in services.msc.

*****CAUTION"""""
If your Windows 11 computer is using either WSL (WIndows Subsystem for Linux), or MDAG (Microsoft Defender Application Guard) , then disabling ICS will break both these features.
With ICS disabled, WSL will flag error "There are no more endpoints available from the endpoint mapper."
Disabling ICS without breaking MDAG:

ICS is enabled by default in Windows, and ICS must be enabled in order for Application Guard to function correctly. We do not recommend disabling ICS; however, you can disable ICS in part by using a Group Policy and editing registry keys.
1. In the Group Policy setting, Prohibit use of Internet Connection Sharing on your DNS domain network, set it to Disabled.
2. Disable IpNat.sys from ICS load as follows:
System\CurrentControlSet\Services\SharedAccess\Parameters\DisableIpNat = 1
3. Configure ICS (SharedAccess) to enabled as follows:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Start = 3
4. (This is optional) Disable IPNAT as follows:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IPNat\Start = 4
5. Reboot the device.

Click to expand...

Source: FAQ - Microsoft Defender Application Guard (Windows 10) - Windows security

iko22 said:

On the Windows 11 PC, you could try disabling then re-enabling the ICS service in services.msc.

*****CAUTION"""""
If your Windows 11 computer is using either WSL (WIndows Subsystem for Linux), or MDAG (Microsoft Defender Application Guard) , then disabling ICS will break both these features.
With ICS disabled, WSL will flag error "There are no more endpoints available from the endpoint mapper."
Disabling ICS without breaking MDAG:

Source: FAQ - Microsoft Defender Application Guard (Windows 10) - Windows security

Click to expand...

I can't see where I can disable/enable ICS in services. I can only find stop/start, which I did and which had no effect.

Right-mouse click on the Internet Connection Sharing (ICS) Service in Services.msc. There will be a drop-down list of items to choose from. Select Properties, then change the Startup type to Disabled. Close the Properties Windows and check the Startup type now reflects the change made. Then go back into Properties from the Right-mouse click on ICS, and change Startup type back to Automatic.

iko22 said:

Right-mouse click on the Internet Connection Sharing (ICS) Service in Services.msc. There will be a drop-down list of items to choose from. Select Properties, then change the Startup type to Disabled. Close the Properties Windows and check the Startup type now reflects the change made. Then go back into Properties from the Right-mouse click on ICS, and change Startup type back to Automatic.

Click to expand...

Ok, thanks for the info. I've done the disabling and automatic startup. Applying the change each time and restarted the PC. I still get no internet on my Ethernet adapter.

Does it matter if my wifi profile is public or private? I've set it to both, with the same result of no internet on the Ethernet adapter.

BTW - I do have a local and an admin account on my PC. I do all this work as the admin account. But I mention this because I've seen having multiple accounts on a PC cause issues before. (I use the local account for security reasons. You tend not to get viruses/trojans/etc installed without admin rights)

It might be worth checking to see if your computer is fully Updated.

There was an ICS issue in the early June Update, last month. It was superseded with another Update mid June. So, if that is the issue, a fully Updated computer would solve it.

ksaro1 said:

BTW - I do have a local and an admin account on my PC. I do all this work as the admin account. But I mention this because I've seen having multiple accounts on a PC cause issues before. (I use the local account for security reasons. You tend not to get viruses/trojans/etc installed without admin rights)

Click to expand...

Yes, that is exactly why it is advisable to have non-admin used accounts. Shouldn't affect ICS as that in the system layer. If I see anything, then I'll post it here.

iko22 said:

It might be worth checking to see if your computer is fully Updated.

There was an ICS issue in the early June Update, last month. It was superseded with another Update mid June. So, if that is the issue, a fully Updated computer would solve it.

Click to expand...

Yes, I read that too. But my PC is fully updated. I am a member of the development rollout though. So would it have rolled out the same update?

ksaro1 said:

Yes, I read that too. But my PC is fully updated. I am a member of the development rollout though. So would it have rolled out the same update?

Click to expand...

Oh, I forgot to mention that in the network adapter section of Control Panel whenever I choose Diagnose for either the WiFi or Ethernet adapter that this fails with an error message "An error occurred loading the troubleshooter". When I look at the error details the error id is 0x80004005

Check Event Viewer for Network Sharing / Troubleshooter errors or warnings. These messages might provide more detail, and detail the error source.

I have the same problem!

I have a Windows 11 Pro (fully updated) system with two Ethernet connections, one built in (Intel I225V) and one USB 3.0 to gigabit Ethernet adapter (Asix AX88179).

I set up ICS to share the internet from the Intel to the Asix adapter but the client is not receiving an IP from the DHCP server. On a whim I setup a static IP in the 192.168.137.x range with a gateway of 192.168.137.1 (The expected ips that ICS sets up) on the client and the Internet connected instantly but if I leave the settings to automatically receive addresses then the connection is dead.

It seems like the ICS DHCP server isn't working or something, so how can I get client devices to receive IP addresses from the ICS host?

I also tried the same thing on a Win 10 laptop sharing it's wifi connection and the same thing happens, no DHCP assignment and setting a static IP on the client works instantly.

Thank You!