How many sub domains can be created inside Azure DNS Zone for one domain

Question

Hi Team,

I have purchased a domain from Godaddy and want to create n number of subdomains inside that domain. I can see a capping of creating only 500 subdomains in Godaddy. So to overcome that I want to use Azure DNS zone service, and having a few queries on the same, please help with it.

1. How many subdomains I can create inside one domain in the DNS zone(looking for the exact count, if any limitations are there)
2. What will be the uptime for DNS zone service, and how can I achieve the highest uptime over there?
3. How will the cost work with AZure DNS Zone? (I will be having one domain and n numbers of subdomains inside this)
4. how many max requests can be processed (request/second) with this service? is there any throttling or capping?
5. Can I create a Multilevel of Subdomains? (https://abc.xyz.contoso.com), and if yes can I protect the same with a wildcard SSL certificate?
6. Do Azure traffic manager and application gateway support multi-level subdomains?

Answer 1

@Harsh Thakor

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 create about 500 subdomains in Azure.

Wrt creating subdomain in Azure,

• To delegate an Azure DNS subdomain, you must first delegate your public domain to Azure DNS
• Delegate a domain to Azure DNS
• After which, Create a Sub domain : https://learn.microsoft.com/en-us/azure/dns/delegate-subdomain

Wrt your queries,

1)How many subdomains I can create inside one domain in the DNS zone(looking for the exact count, if any limitations are there)

• I do not think there is a limitation on number of "subdomain"
• However, there is a limit of 250 Public DNS zones per subscription.
• And I believe each subdomain is actually considered as a DNS Zone in Azure. Meaning, you could only have 249 suddomains + 1 domain per subscription.
• This could be averted if you use multiple subscriptions. More of a work around
• Refer : Azure DNS limits

2)What will be the uptime for DNS zone service, and how can I achieve the highest uptime over there?

• Azure DNS has 100% SLA
• Azure Updates : Azure DNS
• Also, Azure DNS FAQ : What is the SLA for Azure DNS?

3)How will the cost work with Auzre DNS Zone? (I will be having one domain and n numbers of subdomains inside this)

• DNS Pricing

4)how many max requests can be processed (request/second) with this service? is there any throttling or capping?

• Azure DNS is a global service and that's backed by our diverse, geo-redundant DNS infrastructure.
• And as such, there is no such capping

5)a. Can I create a Multilevel of Subdomains? (https://abc.xyz.contoso.com)

• Yes, this will work and the process is same as delegating a subdomain.

b. if yes can I protect the same with a wildcard SSL certificate?

• This depends on the service you are going to use.
• As we do not provide you the certificate, your application and infrastructure should support wildcard.
• DNS has no impact here.

6)Do Azure traffic manager and application gateway support multi-level subdomains?

• Traffic Manager
  • The question does not apply
  • As you only configure CNAME to point to Traffic Manager FQDN and from there, Traffic Manager is going to use it's own FQDN and not going to validate the custom domain.
• App Gateway
  • Yes
  • App Gw supports wildcard host names and as such, this should support multi-level domains.
  • https://learn.microsoft.com/en-us/azure/application-gateway/multiple-site-overview#wildcard-host-names-in-listener

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

Thanks,

Kapil

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