RFC 6303 and bind 9.9.0

Spain, Dr. Jeffry A. spainj at countryday.net
Thu Mar 1 20:59:11 UTC 2012

>> Just for clarification, do I understand correctly that if none of the 
>> empty zones described in RFC 6303 are set up explicitly in the bind 
>> 9.9.0 configuration file, then bind 9.9.0 will process them as such 
>> anyway using built-in generic zone processing rules?

> Yes.  To expand a bit on Mark's answer, all of the namespaces covered by RFC 6303 have built-in empty zones in BIND 9.9, and these zones are activated by default in any view that supports recursion.  No configuration should be necessary.

> If you want to set up reverse DNS for a private network in a nonroutable address space, you can go ahead and do so; zones that you configure override the built-in zones.

Thanks. This works as you say if I remove the explicit configuration for the empty zones, as verified by adding the option 'zone-statistics yes;' and running 'rndc stats'.

Also I see that bind 9.9.0 uses built-in root hints if those are not explicitly configured. If the root hints are updated on ftp://rs.internic.net/domain/, would it require a new build of bind to incorporate them, or is bind able to update its built-in root hints by some other means?

Finally it appears that aside from the built-in empty zones, a forward lookup zone for 'localhost.' is  still required to prevent bind from attempting to resolve this name over the Internet. Reverse lookup zones for and ::1 are also required if it is necessary to resolve those addresses to the name 'localhost.' Is it still considered a best practice to explicitly configure these localhost-related zones on recursive resolvers? I see this point addressed in RFC 1912, but don't see anything in RFC 5735 and RFC 6303, which have superseded it.

Jeffry A. Spain
Network Administrator
Cincinnati Country Day School

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