reverse cidr zones

[Barry Margolin]

In article <cgimb0$d8q$1 at sf1.isc.org>,
 Jeff Stevens <jstevens at vnet.ibm.com> wrote:

> Well, if we have the zone 192-255.185.145.12.in-addr.arpa. defined, does 
> only the parent zone (at the ISP, in this case) need the CNAME records or 
> does the authoritative DNS also need CNAME records?

Just the parent zone.

> I keep thinking there will be a problem where a client configures his DNS to 
> be our authoritative DNS, but then can't find the PTR because he first 
> queries our DNS and we don't have the CNAME records (they're in the parent 
> zone at the ISP).

If clients are supposed to be using your nameserver in their resolvers, 
your server should be configured to recurse for them.  So your server 
will look in the parent domain and find the CNAME records.

To optimize this, it's a good idea to configure your server as a slave 
server for the parent zone.  This way, your server can resolve your 
reverse DNS for its clients even when your Internet connection is down.  
It's also not a bad idea to have your ISP configure the parent zone 
server as a slave for your zone.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***