Trouble configuring forwarders for reverse zones.

[Chris Buxton]

On Apr 8, 2009, at 3:00 AM, M-lists wrote:
> One further thing, I'll be moving things around on our network soon,  
> and
> this means we'll have a classless subnet soon.  So if we moved one  
> of our
> Windows subnets to 10.1.1.0/24, how would I forward reverse queries  
> for this
> subnet to say 10.1.1.1?

When you say "classless subnet", what do you mean? A /24 is not a  
classless subnet as I understand the phrase.

If you really do mean the same thing I do when I use that phrase, a  
subnet such as a /25 or /26, the first thing I would ask is why do  
this? You have 10/8 to work with. If you mean a classless subnet such  
as a /22 or /21, it's easier to just create the individual /24 reverse  
zones than to create a classless subnet reverse zone.

In general, a classless subnet reverse zone relies on CNAME records to  
"move" the PTR record owner name to a new name, in an artificial zone.  
This requires a parent zone to create the CNAME records. (For zones  
larger than /24, use DNAME records instead of CNAME records.) So your  
BIND server might need a 10.1/16 zone, or possibly a 10.1.1/24 reverse  
zone - a parent zone using the standard naming convention that can  
then delegate artificial subzones elsewhere and can contain the CNAME  
or DNAME records needed to rename the PTR records into the subzone.

Chris Buxton
Professional Services
Men & Mice