-1

I'm trying to add a PTR record (reverse DNS) in Azure, but I'm not sure what should be the value in the PTR DNS record, My azure settings are:

DNS NAME people-dns.cloudapp.net

HOST NAME people-dns

PUBLIC VIRTUAL IP (VIP) ADDRESS 137.117.11.18

INTERNAL IP ADDRESS 100.68.96.97

The DNS name points to the mail server...

I understand that I don't need to run any PowerShell commands if I'm using the default DNS name (but maybe I'm wrong?)

I was simply adding a PTR record (using Google Domains) with value people-dns.cloudapp.net for the domain, but I don't know if I need to specify some IP addresses or type it reversed like I saw in here

enter image description here

I found out that the PTR record is critical to avoid email rejections from GMail as I'm trying to resolve a problem where email ends up as SPAM for GMail users when they get it for the first time...

Do you think I should add or change anything?

Community
  • 1
  • 1
Yovav
  • 2,557
  • 2
  • 32
  • 53

2 Answers2

4

The thing to remember about PTRs is that they're a reverse lookup. The name of the record represents your IP address and the value contains your DNS name.

As a result, they don't live in the DNS zone that maps to that DNS name at all! They live in separate, special zones called 'ARPA' zones (see here to learn more). These zones are owned by the organization owning the IP block you are using - in this case, Microsoft.

Microsoft Azure provides the ability to specify the PTR record associated with the IP address assigned to your service (here's how). Since this resides in the Microsoft-owned ARPA zone, you do this completely separate from your normal DNS zone management.

Regards,

Jonathan Tuliani, Program Manager, Azure Networking - DNS and Traffic Manager

Jonathan Tuliani - MSFT
  • 1,158
  • 7
  • 10
0

For the record, my DNS PTR entry on Google Domains was correct (it has to include "." at the end)

The command I used to add a reverse DNS on Azure looks like this:

Set-AzureService -ServiceName "people-dns" -Description "people-dns reverse DNS" -ReverseDnsFqdn "people-dns.cloudapp.net."

You can also use Get-AzureService to set the name to be used and confirm the service status

Also, there are web sites such as mxtoolbox.com that can check if the PTR record is valid, you can also check it manually - see my other question: How to verify that Azure Reverse DNS is working properly?

Community
  • 1
  • 1
Yovav
  • 2,557
  • 2
  • 32
  • 53