Queries to DNS Blackholes don't respond

[/dev/rob0]

On Wed, Apr 18, 2018 at 11:44:27AM -0300, Roberto Carna wrote:
> Dear, I have impelmented a BIND9 server. It works OK, but some days
> ago an application failed because it needed to resolve the reverse of
> some IP addresses from range 10.x.x.x, and they waited for a long time
> and failed, because they need a NXDOMAIN fast response.
> 
> I don't want to make a local zone 10.IN-ADDR.ARPA,

You don't need to.  See the "built-in empty zones" section of the 
BIND 9 ARM, chapter 6.

> because I want to
> use the two public nameservers from Internet:
> 
> BLACKHOLE-1.IANA.ORG (192.175.48.6)
> BLACKHOLE-2.IANA.ORG (192.175.48.42)

What??  Why?  Those are not supposed to be used.  BIND now includes 
empty zones for all RFC 1918 and other reserved netblocks which 
shouldn't ever appear on the open Internet.

If you use some of these networks inside your organization, you can 
have authoritative zones for the corresponding in-addr.arpa zones.

[snip]
> Is it OK that I do? Are blackholes servers useful for this purpose ?

Not at all.  That's why we have the automatic empty zones.  Sadly, 
many distributors are not aware of the feature, so they distribute 
named.conf with kludges.
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