Hyper-V, Wi-Fi and IPv6 autoconfiguration doesn't work

Marcus Büttemeyer 391 Reputation points
2022-07-28T17:05:45.017+00:00

Hello, since my ISP recently (and finally) enabled IPv6 for it's customers, I'm now trying to migrate to native IPv6, as opposed to using tunnelbroker.net.

I have 2 Hyper-V hosts running 2019 with Ethernet for the internal network and Wi-Fi to connect to my provider's LTE router on the window sill. Every host has 2 external virtual Switches: one for the Ethernet and one for Wi-Fi, with the Wi-Fi being disabled for the management operating system in Virtual Switch Manager. In this case, a current Win10 VM I use for testing did not even get an IPv6 address :-(

So per this post I set the "NetworkCategory" for the Wi-Fi interfaces to "Private" for both the the host and the VM. I also enabled the interface for the management operating system with IPv4 and 6. Now the host works just fine, ping -6 to the outside goes through. The VM seems OK too, it has everything it should need: IPv6/Prefix (origin RouterAdvertisement), temporary IPv6, DNS servers and default gateway (both the same as the host). Still no dice with pinging to the outside using IPv6.

On the other hand the same host runs another Win10 VM connected to the internal Ethernet (running radvd and W2019DHCPv6) and I've never had any problems with that. Also the router itself works fine, since the problematic VM also has a Wi-Fi interface attached via DDA and connecting to the router that way, everything works. Also note that the VM uses an external vSwitch connected to a Wi-Fi interface which gives you an additional bridge interface...

Does anybody have any ideas? Please! My client provides me with a Hyper-V environment for teaching and I'd really like to stick with it. But I'd also like to get rid of IPv4 permanently which requires native IPv6 in my home office.

Windows Server
Windows Server
A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.
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Hyper-V
Hyper-V
A Windows technology providing a hypervisor-based virtualization solution enabling customers to consolidate workloads onto a single server.
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  1. Marcus Büttemeyer 391 Reputation points
    2022-07-31T12:57:05.443+00:00

    "Dear Microsoft, IPv6 is not your enemy. On the contrary, it's going to become your best friend. Or, given past experiences, more likely your children's but definitively your grandchildren's best friend! I always wondered why IPv6 uptake wasn't faster? Know I know: it's you (and some equally screwed up ISPs). What annoys me the most is that you make it look like it should work, but it doesn't :( First with DNS64 and now with Hyper-V." Sorry for venting, back to business.

    Workaround: Connect the Wi-Fi card directly to the VM using Discrete Device Assignment (DDA). Then install the necessary drivers in the guest OS and configure the interface. Though this should work, it has several drawbacks: 1) DDA has additional requirements for the VM configuration. 2) You loose the flexibility to connect several VMs to one external Wi-Fi switch. 3) It only seems to work on servers, not clients (W10/11).

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  2. SaoSilvestre 121 Reputation points
    2024-01-22T10:56:05.67+00:00

    Hi!
    I have observed the same behaviour described by Marcus: IPv4+IPv6 on host and guests when using (Ethernet) cable, no IPv6 at all (even for the host) when using WiFi. Solution? None so far. Note: I used to have IPv6 via WiFi prior to the installing of Hyper-V.

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