DNS settings for GUEST networks

> 3. I have DNS servers on my internal network ( pihole )

> 5. [...] GUEST network [...] NOT allow the acess [...]

> [...] GUEST network CAN'T access the DNS servers [...]

   I suspect that no one writing the firmware considered this situation.
(At least not enough to deal with it.)

> Is there any way to setup the R7500 to use a diferent DHCP and DNS
> address that are specific for the GUESTnetwork ?

   So far as I've seen, Netgear consumer-grade routers offer no
user-configuration options for their DHCP servers (other than pool range
and Address Reservation).

> If not , how can I allow the GUEST network access only the 2 DNS
> servers addresses on the internal network ?

   "Allow guests to see each other and access my local network" seems to
be binary, too.

   If you're running a Pi-hole for DNS, then I'd guess that you could
also run your own DHCP server, which might let you customize the DNS
server settings provided to particular clients, but I see no way to get
around the "access my local network" prohibition for "guests".  At least
not with the Netgear firmware.  You might have a better chance with
third-party firmware, if any exists for your model.

      https://community.netgear.com/t5/x/idb-p/idea-exchange-for-home

   I wouldn't hold my breath.