Server 2003 & Trusts between domains

I have three domain controllers behind one router.  The three servers all run Server 2003 Enterprise and are on the following IP set:


I want to establish trusts between the three domains so all users can authenticate to each domain as needed.  After going thru the wizard, I receive a failuire errors telling the user already exists.

I'm looking for step-by-step instructions and help on setting up these trusts.  I am using my domain names (ie: domain1, domain2, domain3) when I try to set up these trusts, and I am attempting two-way trusts in the wizard.

Can someone walk me thru this, step-by-step, inclusing what I type in each box, so I can get it down?

Thank you

Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

If these domains are all in the same forest, they trust each other already.

You should already be able to log onto the other domains using the UPN (

crp0499CEOAuthor Commented:
Well, they are all on the same IP set if that's what you mean.  When I ran dcpromo on them, I made each one a new domain controller and created a new forrest.
crp0499CEOAuthor Commented:
PS: I can log into each one, but it's becasue I created the same user names and passwords in all three domains.  In the future, I'd like the other two to be updated when I add a new user in the first domain.
Cloud Class® Course: C++ 11 Fundamentals

This course will introduce you to C++ 11 and teach you about syntax fundamentals.

crp0499CEOAuthor Commented:
I figured out that I had not raised my servers to the Server 2003 domain/forest levels.  I've done that and identified that I want to establish a forest trust.

However, when I get to the end of the wizard, I am asked to provide a username and password who has access to domain 2.  I put it a user that exists in domain 2 and who has access to establish the trust, and I still get the error that the trust failed and the user already exists.
First off, the users will not populate all 3 server when create in one domain.  You'll need to remove duplicate users on the other servers.  Just leave the users on the domain they belong to and use user@domain to log in when NOT in their home domain.

When you supply credentials to the wizard for the opposite domain, use DOMAIN\Administrator in the username box.


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
crp0499CEOAuthor Commented:
Thank you Netman66!

Got it working like I wanted...

It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Windows Server 2003

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.