CAX80 How do I block specific IPs?

> The problem is some Google smart home devices use hard coded DNS and
> bypass my recursive DNS server.

   And that's a "problem" because?

   Many Internet-of-Junk devices use a hard-coded DNS server for some
purposes.  Generally for very good reasons.

> If I can block googles DNS servers (8.8.8.8 and 8.8.4.4) then those
> smart devices will be forced to use my DNS.

   You think that you can bend them to your will through frustration?

   I know nothing, but I'd expect them to stop working, because they
don't trust your personal DNS server.  Which would be a wise approach
for IoJ (or general gizmo) security.

> [...] It's usually called IP blocking or static routes. [...]

   It is?  By Netgear?

   I can see how one might create a purposely defective static route to
achieve such a result, but I don't recall seeing a static-route
capability in any Netgear cable modem+router models.  Plain router,
yes; DSL modem+router, yes.  (Must be a feature.)

> Can this super expensive router/modem really not do a simple IP block?

   Looks that way to me, at least not using a static route.  Possibly
interesting (including an authoritative response):

      https://community.netgear.com/t5/x/x/td-p/989893