I made a virtual Machine with an mail server. I want to add a ptr Record.

Question

For Testing Purpose made a virtual machine and setup a Mail server. Everything form the Server Site and Access from external is working as planed. But to make i right i wantet do add a PRT record. so i created a Zone with an in addr record with the ip the vm received. I hat do errors. But when i check with mxtoolbox ptr i do not receive the record. Does anyone have any experiance with this?

Answer 1

@Aycholos Escher, Heinzer-it AG ,

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I understand that you would like to add a PTR record to the Public IP of your VM.

Please let me know if my observation is incorrect.

For this to work, you must have a valid DNS name label configured in your PIP Configuration.

• See :
  • 
• Note : DNS name label provides A record and not PTR

Once the above is done, you can proceed to configure the PTR record.

• There are certain conditions to define a PTR record,
  • The DNS name for the public IP address: contosoapp1.northus.cloudapp.azure.com.
  • The DNS name for a different PublicIpAddress in the same subscription, such as: contosoapp2.westus.cloudapp.azure.com.
  • A vanity DNS name, such as: app1.contoso.com. As long as the name is first configured as a CNAME pointing to contosoapp1.northus.cloudapp.azure.com. The name can also be pointed to a different public IP address in the same subscription.
  • A vanity DNS name, such as: app1.contoso.com. As long as this name is first configured as an A record pointing to the IP address 23.96.52.53. The name can also be pointed to another IP address in the same subscription.
• See : Validation of reverse DNS records

What this states is that, (from my example)

• You can add the PTR record as "domainlabel.centralindia.cloudapp.azure.com" to your Public IP or any Public IP in the subscription without any additional configuration.
• If you want the PTR record to be a custom one, say "myapp.mycompany.com" , then the "myapp.mycompany.com" should resolve to your Public IP or any other Public IP in the subscription either via A record or CNAME record.
  • Only then Azure will let you add "myapp.mycompany.com" as PTR record.

You can find the Powershell command here.

Kindly let us know if this helps or you need further assistance on this issue.

Thanks,

Kapil