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Sorry, I know this is a rather lazy question, my server experience is limited to OS X, I'm hoping a Windows guy can "explain it to me like I'm five"

I'll need to help configure a bunch of iPads/iPhones to use Exchange shortly, and I'm sure some of the users will give me inaccurate authentication details. Rather than send them packing, I'd like to be able to make an educated guess at what it might be based on the info they do know, but I'm still a bit fuzzy on the following:

• do all versions of Windows Server follow the same rules for the AD Domain (eg: is it based on FQDN? NetBIOS name? totally arbitrary?)?

• is an AD Domain case-sensitive?

Edit: I'm not asking what is the difference between the two (yes, we use DNS on the Mac too). The question is rather what is the relationship between the two. Do they need to match, basically.

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Are you setting up an AD domain and Exchange from scratch? If so, hire a contractor to do it right; free advice on the internet isn't going to do the job right. – mfinni Sep 29 '11 at 3:19
If not, work with your AD/Exchange team, don't depend on the users. – mfinni Sep 29 '11 at 3:20
The Exchange accounts aren't ours, else I'd have the details. I'm just configuring the phones. Makes my question even lower quality really, as it's more of a client issue – username Sep 29 '11 at 4:22
up vote 6 down vote accepted

The DNS suffix of a domain joined computer is the name of the Active Directory domain to which the computer is joined, which is also the DNS namespace for the domain.

So, you have a computer named "computer1" in an AD domain named "mydomain.local":

The NetBIOS name for the computer is computer1

The name of the AD domain that the computer is joined to is mydomain.local

The DNS suffix for the computer is mydomain.local

The AD DNS zone for the domain is mydomain.local

The FQDN of the computer is computer1.mydomain.local.

The NetBIOS name for the domain is mydomain (although it is possible to create a NetBIOS name for the domain that doesn't match the DNS name for the domain).


Incidentally, in Windows NT 4 it was possible for a computer to have a different DNS host name than the NetBIOS name (multiple DNS host names in fact), but I don't think that's been possible since Windows 2000, due to AD's integration with DNS.

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So the AD domain is pretty much the DNS zone. Thank you! I worry too much :) – username Sep 29 '11 at 4:34
The DNS suffix isn't always the FQDN on the AD domain. – MDMarra Sep 29 '11 at 10:58
@MarKM: I'm not aware of a case where it wouldn't be. Can you explain? Thanks. – joeqwerty Sep 29 '11 at 11:20
You can change it to whatever you want either on the local computer or via GPO. It's still a domain member. It happened to us on a few machines "accidentally" during a domain migration and they continued to work fine. – MDMarra Sep 29 '11 at 11:22
Gotcha. I actually am aware of that but didn't think that would be applicable in an AD domain (in 99.999% of cases). I thought you were referring to some other reason where it wouldn't be the case (and maybe there is, I don't know). Thanks much for the reply. – joeqwerty Sep 29 '11 at 12:44

An active directory domain name is a FQDN. The NETBIOS name is, by default, the shortened version of the FQDN. This can be changed, so it is not always the same.

I have no idea what you mean by the 2nd question.

It is case insensitive.

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I deleted Question 2, since it basically just restated "is it based on FQDN?" from Question 1 – username Sep 29 '11 at 4:26

It is possible to address a Windows 2003 (and maybe 2008) server with multiple hostnames using DNS CNAMEs and adding SPNs to the AD object for the server. You would also need to modify the "DisableStrictNameChecking" registry entry. All three of these are required to address a server by multiple NetBIOS (single-label) hostnames.

Refer to:

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