[dns-operations] PTR Records for Broadband Network?

Michele Neylon - Blacknight michele at blacknight.com
Wed Nov 23 14:06:17 UTC 2022


Sorry about the email format - Outlook has a mind of its own at times :(

We have been trying to contact the various companies our clients are having issues with. I've personally spent hours trying to get Ticketmaster to escalate my query to somebody with a $clue, but got stuck in their CS system from hell :(

The PTR records are fine - many of them have been there for many years. Somebody else pointed out to me offlist that some are missing A records, so we'll address that.
We've checked the IPs against blacklists and nothing is showing that we can find.
While *some* of the IP ranges we are using might be "secondhand" several of them are shiny and new and were never used prior to them allocated to us. Of the "used" ranges none were problematic and some come from another Irish ISP that has been consumed via M+A (not by us!).

If you or anyone else can suggest mailing lists where I might stumble across people who work for some of these companies please do let me know - it'd be appreciated.




Mr Michele Neylon

Blacknight Solutions

Hosting, Colocation & Domains


Intl. +353 (0) 59  9183072

Direct Dial: +353 (0)59 9183090


Blacknight Internet Solutions Ltd, Unit 12A,Barrowside Business Park,Sleaty Road,Graiguecullen,Carlow,R93 X265, Ireland  Company No.: 370845

From: Joe Abley <jabley at hopcount.ca>
Sent: Wednesday 23 November 2022 13:55
To: Michele Neylon - Blacknight
Cc: dns-operations at dns-oarc.net
Subject: Re: [dns-operations] PTR Records for Broadband Network?

[EXTERNAL EMAIL] Please use caution when opening attachments from unrecognised sources.

Hi Michele,

On Nov 23, 2022, at 07:46, Michele Neylon - Blacknight via dns-operations <dns-operations at dns-oarc.net> wrote:


Hmm :-)

Many many moons ago we setup the PTR records for our network using a template that clearly flagged that the IPs were static and used for hosting.

The result was that the IP would end up with a PTR record of 239-13.colo.sta.blacknight.ie

Fast forward to 2022 and we now offer broadband to both businesses and consumers, but unfortunately some streaming services and others are blocking access. So our users have issues with Disney+, All4, Netflix and Ticketmaster to name but a few examples. One of the issues appears to be the PTR records.

It might be worth reaching out to some of the people you know your customers are struggling with specifically and seeing what they are looking for. The presence and functional correctness of PTR records is known to be used as one heuristic for e-mail abuse ops; I hadn't heard of it for things like Netflix but what do I know?

I assume these PTR records you have made are correctly published. Have you checked that the PTR targets (the 239-13.colo.sta.blacknight.ie name and its friends) themselves resolve back to the right address?

Are the address ranges you are using for your customers tainted through some prior abuse, e.g. by some other organisation that used to use them? Do they appear on any of the usual blacklists?

I have seen informal guidance to access providers in the past on what naming conventions are useful. I can't seem to find any of them right now but your naming scheme does not seem ridiculous. I would be surprised if that's the problem.

You might want also to ask this question on the kind of more general lists that access and content providers hang out on.


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