[ale] Question DNS Reverse Zones

[Derek Atkins]

Michael Trausch <mike at trausch.us> writes:

> Reverse delegation isn't possible with IPv4 records with CIDR subnets. Well,
> kind of. Not in a std way, anyway. IPv
> 6 records support it because of their nybble granularity.

Actually, there is a standard way to do this by using CNAME records to
point to a CIDR-INADDR domain.  Let's say that you have the domain
w.x.y.z/28, then you can use CIDR-Inaddr to get that domain delegated to
you.  In y.x.w.in-addr.arpa (the ISP's zone) you put:

z_28 NS (client servers)
z CNAME z.z_28
z+1 CNAME z+1.z_28
...
z+15 CNAME z+15.z_28


Then in your servers you make a zone:

z_28.y.x.w.in-addr.arpa

z PTR ...
z+1 PTR ...
...
z+15 PTR ...

> Anyway, your ISP will have a procedure to use for asking for an rDNS update.
> It is probably buried somewhere though.

This is probably easier.

>   Mike
>

-derek
-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
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