nanog mailing list archives
Re: Anyone from AT&T DNS?
From: Christopher Morrow <morrowc.lists () gmail com>
Date: Wed, 4 Oct 2017 23:08:16 -0400
On Wed, Oct 4, 2017 at 11:03 PM, Matt Peterman <mpeterman () apple com> wrote:
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.
there are more than 1 way to skin the cat, sadly. This tripped me up on a customer connection for a while as well, the RFC example I provided earlier is also valid.
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)
according to the rfc you can.
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…
nope, they are just following the rfc provided path for this. yes it looks screwy, yes it also works fine.
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> 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 describes, or in a (perhaps more wordy fashion) in 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. 129 IN PTR bar.you.com. etc...
Current thread:
- Anyone from AT&T DNS? Matt Peterman (Oct 04)
- Re: Anyone from AT&T DNS? Christopher Morrow (Oct 04)
- Re: Anyone from AT&T DNS? Matt Peterman (Oct 04)
- Re: Anyone from AT&T DNS? Christopher Morrow (Oct 04)
- Re: Anyone from AT&T DNS? Matt Peterman (Oct 04)
- Re: Anyone from AT&T DNS? Christopher Morrow (Oct 04)
- Re: Anyone from AT&T DNS? Matt Peterman (Oct 04)
- Re: Anyone from AT&T DNS? Christopher Morrow (Oct 04)
- Re: Anyone from AT&T DNS? Matt Peterman (Oct 04)
- Re: Anyone from AT&T DNS? Jay Farrell via NANOG (Oct 05)
- Re: Anyone from AT&T DNS? Mark Andrews (Oct 08)
- Re: Anyone from AT&T DNS? Matt Peterman (Oct 04)
- Re: Anyone from AT&T DNS? Christopher Morrow (Oct 04)
- Re: Anyone from AT&T DNS? Mark Andrews (Oct 08)