Forwarding queries for domains with particular nameserver IP address (or name)?

[Viktor Dukhovni]

Some nameservers that serve a lot of domains have rate limits low enough
that I can't reliably use them.  I'd like to avoid direct queries to these
and instead forward to a bunch of the usual public resolvers.  Is there
any way to get unbound to do that?

	if address(nameserver) in (192.0.2.1, 192.0.2.2, 192.0.2.3)
	then forward to one of (1.0.0.1, 1.1.1.1, 8.8.4.4, 8.8.8.8, 64.6.64.6, 64.6.65.6)
        else direct query

The effect would be that no queries are ever sent to 192.0.2.1, 192.0.2.2, 192.0.2.3
The result should still be subject to validation, ...

-- 
	Viktor.