Brian

Thank you again for your response, and also thank you for yesterday pointing me 
to the support in open policy for the group.
Currently I don't have any evidence as I have not done the packet captures.

Two of the three outside parties complaining claim their servers look up the 
authoritative name servers for the domain in the email address and then their 
systems dig for reverse lookup against these name servers.

It seems out of spec. but I have 2 parties saying this is normal and how it has 
been done for years. The third is showing the same behavior, but has not stated 
why they think it is occurring yet.  I have asked them for more information and 
they have side they will get it to us. I will look to do some packet captures 
as well.

My guess is our previous servers were running bind and look like they may have 
allow recursive lookups for any requests to the reverse zones. I am looking 
into the configs to see how they were pulling that off with the rest of 
recursion being blocked. Unfortunately the guy who set up our bind servers left 
several years ago.

Thanks
Bryant

----------------------------------------
From: Brian Candler <b.cand...@pobox.com>
Sent: 7/19/19 11:00 AM
To: bryantz-p...@zktech.com, pdns-users <pdns-users@mailman.powerdns.com>
Subject: Re: [Pdns-users] Reverse Lookup zone subnetted
On 19/07/2019 15:52, bryantz-p...@zktech.com wrote:
> Where we are getting into issues is that customers we host e-mail
> servers for are having issues as some email service providers appear
> to be forcing their reverse lookups directly against our powerdns servers.

Can you provide your evidence for that assertion?  Do you have packet
captures?

I can't see any way they could know about your nameservers, unless they
followed the in-addr.arpa delegation which ended up with your CNAME.


_______________________________________________
Pdns-users mailing list
Pdns-users@mailman.powerdns.com
https://mailman.powerdns.com/mailman/listinfo/pdns-users

Reply via email to