Hi Mick, thanks for trying out IPv6-mostly at home. Troubles with Chromecast was actually something I even mentioned briefly in my talk at RIPE 85: https://ripe85.ripe.net/archives/video/923/ I guess you would get similar issues with many consumer-grade IoT devices whose security model works like: - if you are in the same L2 network, you can do everything - if you are not in the same L2 network, you cannot do anything However, regarding Chromecast, I think I might have a solution for you (not tested though): As far as I know, Chromecast is since some firmware update in the past, capable* of running on an IPv6-only Wi-Fi network. *) by that I mean you can cast the content from Android YouTube app to it. The casting will still not work with many IPv4-only apps which will just not see the IPv6-only Chromecast. So the issue with IPv6-mostly network and Chromecast lies in the fact that the Chromecast is dual-stack while your phone is IPv6-only. Therefore, I think you can get around this by blocking the MAC address of your Chromecast on your DHCPv4 server and thus forcing it to IPv6-only operation. Let me know if this helps and whether such functionality is useful. Also, chances are that Chromecast Audio, being a discontinued product, didn't get the firmware update enabling IPv6 support, in that case I don't think there's any help. -- Ondřej Caletka