Hi all

I had a task to create a Cross Forest Trust.

I had two independent Forests natively in Windows Server 2008 R2. For example purpose I will name them F1.local and F2.local.

I’m posting this because i found some problems along the way that might help some one if they get into this.

Begin

Do this on Domain Controller of F1.local

Start -> Administrative Tools -> Active Directory Domains and Trusts

Right Click on F1.local -> Properties -> Go to tab Trusts and click on New Trust…

This is pretty straightforward. In the domain camp put F2.local and Next. This is were i got problems. It didn’t recognize that as a Windows Domain, he asks if you want to configure this as a Realm Domain. You don’t, you want Windows Domain trust. This is of course a DNS problem but may not be that simple. I googled and found two types of problems and the solutions for them.

First IPv6 enabled on the interfaces! Go to properties of NIC and deselect IPv6. Now go back to create the Trust! I think that it will still not work. That lead us to the second problem that for sure will solve.
Being this a DNS problem, F1.local cant find F2.local, we will create on the DNS a Conditional Forwarder for each Forest.

On F1.local:

Start -> Administrative Tools -> DNS
Right Click on Conditional Forwarders -> New Conditional Forwarder..

DNS Domain:
F2.local

IP addresses of the master server:
Add here the ip of F2.local Domain Controller

Select the Store this Conditional Forwarder in Active Directory, and replicate is as follows:
All DNS Servers in the forest

OK+ Now repeat the same on F2.local Domain Controller and put the DATA related do F1.local .

Before you go jumping to try to create the Trust, open Command Prompt and do a ipconfig /flushdns .

After this on F1.local you can make the Cross Forest Trust. You only need to this on F1.local, you will choose your options in the steps.

Hope this can help some one. Any questions just post in the comments!

Cheers
pLASTIK

Tags: AD, Microsoft, W2K8, Windows Server