Issues regarding ipv6

[deHakkelaar]

@hyperactive68

And ipconfig /all now shows the following:

 DNS Servers . . . . . . . . . . . : 2a02:a210:223c:a580:6ff6:3714:99f:258c
                                       192.168.178.3
                                       2a02:a210:223c:a580:6ff6:3714:99f:258c
                                       2a02:a210:223c:a580:6ff6:3714:99f:258c

So is it good now?

That looks good for now ...
but that 2a02:a210:XXX address is a GUA (Global Unicast) address as can be seen below:

The prefix (being pushed by your ISP) in a GUA address can change periodically.
Meaning the IP can change and most likely will after a while as with many ISP's.

Preferred is to set the ULA (Unique Local) IPv6 address for DNS which doesnt change:

Use IPv6 ULA addresses for Pi-hole

Many users have reported that frequently changing IPv6 addresses cause page load to be slow or even prevent from working at all. The issues can be fixed by updating the IPv6 address in /etc/pihole/setupVars.conf followed by a run of pihole -g. However, this solution turns out to be very inconvenient since it might be necessary to change the IPv6 address on a regular basis (maybe even multiple times a day). An alternative approach we are currently looking into is the usage of ULA addresses which…

Or if thats not possible, configure the LLA (Link-Local) address of the Pi-hole host.

You can see what IPv6 addresses are configured on the Pi-hole host with below:

ip -br -6 a

And test connectivity from a client PC (Windows/MacOS/Linux) to above mentioned ULA or LLA addresses with below:

nslookup pi.hole <PIHOLE_IPV6_ADDRESS>