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Busy prepping for MS100 exam I need some more insights on sub domains. I have managed tenants that have subdomains but I have never setup a tenant with subdomains.
First question can sub domain be added without the parent domain to a tenant.
Second question from what I have read up a subdomain can only be added if you manage your own dns records with a registrar and and will be automatically verified due the parent to be added. But if it was purchased through Microsoft 365 connect or if you allowing Microsoft manage the name servers, you will not able be add sub domains. My question around the name servers. Im assuming when adding domain to 365 using Go Daddy as example Microsoft will setup the DNS records automatically and this is where Microsoft manages the name servers?
Hi @Brendan Roets ,
As far as I know from my last subdomain setup you don't have to verify your subdomain seperately. But for sure you have to register the default DNS records (MX, SPF and CNAME for autoconfig).
The MS-100 learning path says, that root domains must be added before subdomains. I don't know and didn't found any other docs entry which says something about subdomains only. I know that each domain (with any attendant subdomains) can only be validated to a single Microsoft 365 tenant account. So it's either way not possible to add a subdomain to another M365 tenant, while the root domain is already registered in an M365 tenant.
For second question:
I've never purchased a domain via M365. But i think if you purchase the root domain via M365 you are able to add a subdomain in M365 admin center without additional effort.
If you use a registrar (e.g. Go Daddy) you are able to add a custom subdomain and its own DNS-records.
Yes, you can add subdomains to a tenant, without having the parent domain added. You will have to go over the full verification process in this case. As for changing name servers/using MS managed DNS records, this only makes sense for smaller shops, ones that are not using the domain for anything other than email.
But is it possible to regster the root domain and subdomains in different M365 tenants?
Yes, it is.
@Brendan Roets
I just wanted to check in and see if you had any other questions or if you were able to resolve this issue?
If you have any other questions, please let me know.
Thank you for your time and patience throughout this issue.
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