why duplicate name server value?

Question

Hello, we are working on making about a lot of custom dns.

I checked the current ns and found overlapping(duplicate) values, what is the reason for this? Does it matter again?

As far as I know, ns is usually used to move to a specific ip, but is it because only the azure app service is currently targeted?

Our environment is as follows.
-> app service & service plan
-> dns
-> blob storage

The values of the image appear the same in multiple domains.

Answer 1

Hello @Heeyoung Eom (엄희영) ,

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

The NS records identify the name servers, responsible for your DNS zone. NS records delegate the DNS zone to use the given authoritative name servers and tell which servers can be contacted to obtain the records pertaining to a domain.

In Azure, once you publish a DNS Zone, you will get assigned 4 regional Name servers, each one part of a separate bucket or name server pool.
Azure DNS nameservers will have the following format: ns<1-4>-<bucket>.azure-dns.<com/net/org/info>.

Sometimes, few customers may have been enabled with a feature where their resource group is pinned to a set of name servers. In that case, all the DNS zones created in that particular resource group will have same set of 4 Name servers.
For example, if the said resource group is pinned with bucket “3”. Then using the syntax ns<1-4>-<bucket>.azure-dns.<com/net/org/info>, the nameservers will be: ns1-03.azure-dns.com, ns2-03.azure-dns.net, ns3-03.azure-dns.org & ns4-03.azure-dns.info for all the DNS zones created in that resource group.

It will not affect the creation of new DNS zones and is nothing to be concerned about but it may affect creation of sub-domains in the same resource group.

In general, you can create Parent domain and Sub-domain in the same resource group and they will be allotted with different Name servers set and we create explicit NS delegation to sub-domain from the parent domain.
However, if your resource group is pinned to a set of name servers, this may limit you from creating the parent and sub-domain in the same resource group. Note that, we cannot share same name servers between a parent domain and sub-domain.

If you face any issues while creating sub-domains in the same resource group as the parent domain, then you may need to create a support request to get the backend log confirmation of the feature enablement causing the issue and ask for the feature disablement.

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

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