Child Domain or New Tree?

[msnews.microsoft.com]

I have a question that for some reason I am forgetting the answer to:

What is the main difference between creating a new subdomain (child domain)
in the forest, and creating a new domain in its own tree?

Other than the fact that the child domain will share a contiguous namespace
with the parent, is there any other difference?

The child domain will still be its own entity in the forest, just like the
new domain tree, will it not?

If somebody can kind of clear up this confusion for me. I have to merge a
company into my forest , and i'm not sure whether to merge this new company
as a child domain, or a new tree domain... I'm not sure the
benefits/advantages of either approach, and the company to merge is
extremely flexible with their domain name and namespace options...

 

[Herb Martin]

I have a question that for some reason I am forgetting the answer to:

What is the main difference between creating a new subdomain (child domain)
in the forest, and creating a new domain in its own tree?

The DNS name of the new domain in comparison
to the DNS name of the existing domains is the ONLY
relevant issue in this decision.

If the new DNS name is a natural child of an existing
AD domain DNS name then it will be a child domain
of that existing domain.

If not, it will start a new tree (by definition.)

Other than the fact that the child domain will share a contiguous namespace
with the parent, is there any other difference?
No.

The child domain will still be its own entity in the forest, just like the
new domain tree, will it not?

For creation of the domain there is NO other difference.

There is one VERY MINOR (in almost all other cases)
practical distinction related to kerberos (authentication)
referral paths but for most real world forests this is a
neglible issue and can be "fixed up" with short cut trusts
if there is ever an issue.

If somebody can kind of clear up this confusion for me. I have to merge a
company into my forest , and i'm not sure whether to merge this new company
as a child domain, or a new tree domain... I'm not sure the
benefits/advantages of either approach, and the company to merge is
extremely flexible with their domain name and namespace options...

What is the name of the new domain?

What is the name all the existing domains?

If it is not a natural DNS child of an existing
domain, then it starts a new tree.