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Re: Anyone from AT&T DNS?


From: Matt Peterman <mpeterman () apple com>
Date: Wed, 04 Oct 2017 23:03:38 -0400

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 () gmail com> wrote:



On Wed, Oct 4, 2017 at 10:43 PM, Matt Peterman <mpeterman () apple com <mailto:mpeterman () 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...




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