Windows 10 is ignoring the DHCP configured DNS server

[obroad]

This MIGHT be a Windows thing not a Smart Hub 2 thing but just in case...

I'm using a local DNS proxy for ... reasons. I've configured the Smart Hub DHCP to supply the address of the proxy and for months it seemed to be working.

Recently I've found that the hub's IPv6 address is showing as DNS server (technically the hub's link local address I think) meaning the requests are being resolved by the hub and not by the DNS proxy.

Any ideas.

[jackleach77]

It sounds like your Smart Hub 2 is defaulting to its own IPv6 address for DNS queries instead of using the local DNS proxy you configured, possibly due to an update or configuration change on the hub or a Windows setting affecting DNS resolution. To address this, you might need to manually configure your devices to use the IPv6 address of your DNS proxy, disable IPv6 on the Smart Hub if possible and not needed, or check for any recent updates or changes that might have altered the DNS settings. Additionally, ensure that your DNS proxy supports and is configured for IPv6 if your network uses it.    Best laparoscopic surgeon

[obroad]

I am wondering about disabling IPv6 on the Smart hub, not sure if it is even possible now.

Also I'm aware that I can just set all the computers manually, but I'm looking for a nice tidy DHCP based solution.

Anyway I think I've found a setting on the Smart Hub that works, and that is to go to IPv6 configuration and put the IPv6 address of the proxy in both DNS fields .

And then ...

Don't just use ipconfig /renew, instead physically disconnect and reconnect the network connection. If this works you'll now have the proxy listed five times, and this seems to fill up all the DNS "slots" so it doesn't put the router into the list.

YMMV.

Also the thought just crossed my mind that maybe the Smart Hub has an option to just turn off its internal DNS proxy, which would have been a much simpler solution but I probably didn't even think to look.

[orion_pilot]

The ability to influence the DNS in BT supplied equipment is rudimentary at best.  All DNS on BT supplied equipment typically assumes you will be using BT DNS servers, which actually resolve all IPV4 and IPV6 enquires to their IPV4 DNS Servers.  If you truly want to manipulate your local DNS providers with things like proxies then you will be in the domain of replacing the BT supplied router with your own. That is the only surefire way of ensuring that DNS services in your network are going to reliably use the DNS servers offered up by your DHCP to clients requesting either an IPV4 or IPV6 address.  With some BT supplied routers you can change the IPV4 settings, but there are typically no options for IPV6 DNS, it doesn't even exist on BT network as all DNS is over IPV4 anyway.
Your only other recourse, which is not recommended is to manually set the DNS servers in the IP configuration of each affected Windows10 device, so that they use your DNS servers, but its a simple job for the end user to overwrite this by simply going back to AUTO from manually assigned and the problem is straight back again.