Can't configure rDNS

Question

Can't configure rDNS

NOAM 0

I am trying to configure rDNS for my website.

How do you configure rDNS record if

domain is in another supplier.
Azure is the hosting.

I tried to follow instructions here:

https://learn.microsoft.com/en-us/azure/dns/dns-reverse-dns-hosting

But it doesn't work

KapilAnanth-MSFT 49,611 Reputation points Microsoft Employee Moderator

2023-06-08T09:10:17.9666667+00:00
@NOAM

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 configure rDNS for your website.

Let's assume your domain is "contoso.com"

I take it that the domain name registrar is some third party

And you have successfully delegated and hosted this domain to Azure

Having your domain hosted in Azure or in a different vendor does not matter.

The important thing is that you must own the IP for which you are trying to add a reverse lookup.

The IP ranges represented by the reverse lookup zones must be assigned to your organization, typically by your ISP.

Then you have to delegate the zone with the help of your ISP

Refer : Delegate a reverse DNS lookup zone

After creating the reverse DNS Zone, did you request your ISP to update the name servers?

Cheers,

Kapil
Patchfox 4,176 Reputation points

2023-06-08T10:00:38.38+00:00

Hi NOAM, what do you mean with "Azure is the hosting".? Does it mean you want to use Azure services and Azure IPs with your custom domain and want to have a rDNS flow for this domain?
NOAM 0 Reputation points

2023-06-08T14:05:45.6+00:00

@KapilAnanth-MSFT

What does it mean that my ISP should update the nameservers?

If I update the nameservers everything will fall apart. My ISP has a big red flag that no recoed will be in effect if the name servers will not point to them
Patchfox 4,176 Reputation points

2023-06-08T14:14:46.1866667+00:00

Hi NOAM, then its is not possible to use a custom domain for rDNS setup. You need the permissions and functionality on ISP or Domain hoster site to change the Nameserver to Microsoft ones.
KapilAnanth-MSFT 49,611 Reputation points Microsoft Employee Moderator

2023-06-08T14:21:52.7266667+00:00

@NOAM

The name servers are available in the DNS Zone you have created.

Now, your ISP (which owns the IP issued to you) must update the name servers (for the IPs assigned to you) to the ones provided by Azure so that the rDNS queries are forwarded to the DNS Zone in Azure.

This is the requirement for configuring rDNS.

Thanks,

Kapil
NOAM 0 Reputation points

2023-06-08T14:25:59.73+00:00

@KapilAnanth-MSFT

But in my case the IP is owned by microsoft, and the domain in owned by a different supplier.
Patchfox 4,176 Reputation points

2023-06-08T14:34:22.09+00:00

Hi NOAM, this is what I assumed and asked you in my previous answer. But you still need the possibility to change the DNS Nameserver of your Domain provider to Microsoft ones. Otherwise the resolution and delegation do not work.

EDIT:

Does your service give you an azure owned domain? Which service do you want to use?
Maybe I have another solution.
Grmacjon-MSFT 19,301 Reputation points Moderator

2023-07-07T20:18:39.31+00:00

Hi @NOAM checking to see if the below response help answer your question. Please remember to "Accept Answer" if any answer/reply helped, so that others in the community facing similar issues can easily find the solution. Thanks!

1 answer

Your answer

KapilAnanth-MSFT 49,611 Reputation points Microsoft Employee Moderator

2023-06-08T09:10:17.9666667+00:00

@NOAM

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 configure rDNS for your website.

Let's assume your domain is "contoso.com"

I take it that the domain name registrar is some third party

And you have successfully delegated and hosted this domain to Azure

Having your domain hosted in Azure or in a different vendor does not matter.

The important thing is that you must own the IP for which you are trying to add a reverse lookup.

The IP ranges represented by the reverse lookup zones must be assigned to your organization, typically by your ISP.

Then you have to delegate the zone with the help of your ISP

Refer : Delegate a reverse DNS lookup zone

After creating the reverse DNS Zone, did you request your ISP to update the name servers?

Cheers,

Kapil
Patchfox 4,176 Reputation points

2023-06-08T10:00:38.38+00:00

Hi NOAM, what do you mean with "Azure is the hosting".? Does it mean you want to use Azure services and Azure IPs with your custom domain and want to have a rDNS flow for this domain?
NOAM 0 Reputation points

2023-06-08T14:05:45.6+00:00

@KapilAnanth-MSFT

What does it mean that my ISP should update the nameservers?

If I update the nameservers everything will fall apart. My ISP has a big red flag that no recoed will be in effect if the name servers will not point to them
Patchfox 4,176 Reputation points

2023-06-08T14:14:46.1866667+00:00

Hi NOAM, then its is not possible to use a custom domain for rDNS setup. You need the permissions and functionality on ISP or Domain hoster site to change the Nameserver to Microsoft ones.
KapilAnanth-MSFT 49,611 Reputation points Microsoft Employee Moderator

2023-06-08T14:21:52.7266667+00:00

@NOAM

The name servers are available in the DNS Zone you have created.

Now, your ISP (which owns the IP issued to you) must update the name servers (for the IPs assigned to you) to the ones provided by Azure so that the rDNS queries are forwarded to the DNS Zone in Azure.

This is the requirement for configuring rDNS.

Thanks,

Kapil
NOAM 0 Reputation points

2023-06-08T14:25:59.73+00:00

@KapilAnanth-MSFT

But in my case the IP is owned by microsoft, and the domain in owned by a different supplier.
Patchfox 4,176 Reputation points

2023-06-08T14:34:22.09+00:00

Hi NOAM, this is what I assumed and asked you in my previous answer. But you still need the possibility to change the DNS Nameserver of your Domain provider to Microsoft ones. Otherwise the resolution and delegation do not work.

EDIT:

Does your service give you an azure owned domain? Which service do you want to use?
Maybe I have another solution.
Grmacjon-MSFT 19,301 Reputation points Moderator

2023-07-07T20:18:39.31+00:00

Hi @NOAM checking to see if the below response help answer your question. Please remember to "Accept Answer" if any answer/reply helped, so that others in the community facing similar issues can easily find the solution. Thanks!

Answer 1

@NOAM

If the IP is Azure owned, and you are using a Public IP or Cloud Services(Classic Deployment Model),

You should follow this: Reverse DNS for Public IP address resources.

Prerequisite:

The Public IP must have a FQDN, or in other words, a DomainNameLabel
1. Under your Public IP address, go to Configuration Tab
2. Under DNS name label, enter the prefix you want to use.
3. Select Save at the top of the page.
4. Select Overview in the left menu to return to the overview blade.
5. Verify that the DNS name appears correctly.
Add a DNS CName Record in your domain to point to this Label.
or
Add a A Record in your domain to point to this IP Address

Steps to follow:

Once the A record or CNAME record is configured & replicated, you can go ahead and set Reverse DNS as follows:

$pip = Get-AzPublicIpAddress -Name "<Name of PIP>" -ResourceGroupName "<RG Name>"
$pip.DnsSettings.ReverseFqdn = "<Your custom domain>"
Set-AzPublicIpAddress -PublicIpAddress $pip

Post this, wait for around 15-30 minutes so that the DNS gets propagated.

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

Thanks,

Kapil

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Can't configure rDNS

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