Question about NLB, Clustering, and External DNS

Dbutch1976

Hi Guys,

I'm preparing for 70-296 and I'm just setting up NLB and Clustering on my VMWARE network environment. I see that MS recommends setting up these resources on it's on external DNS domain. My question is should is be a parent with a child domain or two forest root domains?

EG

Constoso.com
\
\
\
\
\
External.Contoso.com

OR


Contoso.com
_______________________/\_______________________
/ \
Internal.Contoso.com External.Contoso.com

The problem with the 2nd exam is that it would seem to require the creation of 3 domains as opposed to 2. I'm fairly certain that the 1st example is the correct one, just would like some assurance.

Thanks!