Anyone from AT&T DNS?

Thu Oct 5 03:03:38 UTC 2017

The correct format is as shown below (this is from another /25 I have from AT&T that has DNS setup correctly) 

$ dig +short CNAME 1.120.232.108.in-addr.arpa
1.0.120.232.108.in-addr.arpa.

So for the block I am having an issue with the CNAME records should be 
For 107.207.168.128 should be 128.128.168.207.107.in-addr.arpa (it shouldn't have “/25” in the middle of it - you can’t even have “/“ in a DNS entry AFAIK)
If I do another address from my block I get $ dig +short CNAME 191.168.207.107.in-addr.arpa
191.128/25.168.207.107.in-addr.arpa.

Again that would should be 191.128.168.207.107in-addr.arpa. 

Somehow AT&T DNS got the “/25” prefix length in all of the  DNS entries…

Matt

> On Oct 4, 2017, at 10:53 PM, Christopher Morrow <morrowc.lists at gmail.com> wrote:
> 
> 
> 
> On Wed, Oct 4, 2017 at 10:43 PM, Matt Peterman <mpeterman at apple.com <mailto:mpeterman at apple.com>> wrote:
> The PTR record CNAMEs for my /25 allocated prefix are all messed up. They are returning as
> $ dig +short CNAME 128.168.207.107.in-addr.arpa
> 128.128/25.168.207.107.in-addr.arpa.
> 
> Which is obviously a completely invalid DNS entry. I have opened a ticket through the web portal for “prov-dns” but Haven’t gotten a response for 7 days.
> 
> If anyone from AT&T DNS or knows anyone from AT&T DNS that can help it would be appreciated!
> 
> 
> isn't this one of the proper forms of reverse delegation in CIDR land? 
> 
> like:
> http://support.simpledns.com/kb/a146/how-to-sub-delegate-a-reverse-zone.aspx <http://support.simpledns.com/kb/a146/how-to-sub-delegate-a-reverse-zone.aspx>
> 
> describes, or in a (perhaps more wordy fashion) in RFC2317?
>   http://tools.ietf.org/html/rfc2317 <http://tools.ietf.org/html/rfc2317>
> 
> I think it may be the case that the NS hosts are not prepared for such a domain/record mapping though... the nameservers that would need to to be authoritative for a zone like:
> 
> 
> 128/25.168.207.107.in-addr.arpa.
> 
> and have a bunch of PTR records like:
> 
> 128             IN PTR foo.you.com <http://foo.you.com/>.
> 129             IN PTR bar.you.com <http://bar.you.com/>.
> 
> etc...
> 
> 