Re: [tlug] Reverse DNS Delegatation

[Pier Fumagalli <pier@example.com>]

On Thu, Jul 18, 2013 at 2:02 PM, Curt Sampson <cjs@example.com> wrote:
> On 2013-07-13 14:00 +0900 (Sat), Shaun Hughes wrote:
>
>> I've been tearing my hair out trying to get an ISP to understand that I
>> would like to buy their product and have them delegate the DNS reverse zone
>> to my DNS Servers.
>
> Unless there's a trick I don't remember, they can't do this unless
> you've contracted for an entire /24 from them, since the zones for
> in-addr.arpa. records are based on octets within the IP address.

Hmm? http://tools.ietf.org/html/rfc2317

ISPs can delegate any sub /24 as needed... For example we host
DNS for our routing network, which is a simple small /27.

Look up our example 64/27.163.183.203.in-addr.arpa.

$ nslookup - 8.8.8.8
> SET TYPE=SOA
> 64/27.163.183.203.in-addr.arpa.
Server: 8.8.8.8
Address: 8.8.8.8#53

Non-authoritative answer:
64/27.163.183.203.in-addr.arpa
    origin = dns.gilt.jp
...

$ nslookup - 8.8.8.8
> SET TYPE=NS
> 64/27.163.183.203.in-addr.arpa.
Server: 8.8.8.8
Address: 8.8.8.8#53

Non-authoritative answer:
64/27.163.183.203.in-addr.arpa nameserver = ns1-46.akam.net.
...