Anyone from AT&T DNS?

Matt Peterman mpeterman at apple.com
Thu Oct 5 03:07:35 CST 2017


You are correct through that that link does show having the CIDR prefix length in the CNAME which is weird because AT&T did not do this on my other /25 block. Interesting… Guess I need to do more digging. 

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...
> 
> 



More information about the NANOG mailing list