Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am unable to install the DNS role with dcpromo.exe when adding a new server to an existing forest.

Current Configuration

I currently have a domain controller running windows server 2008 r2. Let's call it server1. It has one domain on it. Let's call it customer.local.

I have setup a second server, vserver, running the same operating system. It has the hyper-v role installed on it. It is running a virtual, server 2008 r2 box, called server2.

I am now trying to add server2 as a second domain controller in the existing forest with the eventual intention of transferring the FSMO roles and eliminating the first server.


Now, when I add the domain controller server role to the virtual machine, I get the following error:

A delegation for this DNS server cannot be created because the authoritative parent zone cannot be found or it does not run Windows DNS Server. If you are integrating with an existing DNS infrastructure you should manually create a delegation to this DNS server in the parent zone to ensure reliable name resolution from outside the domain.

To correct this issue, I removed the AD DS role and attempted to create a delegation on my first server currently running active directory/dns. However, I do not want to create a subdomain, which appears to be my only option when creating a delegation. It wants me to delgate a "name.customer.local" subdomain.

I decided to take a different tactic. In researching the problem, I found many suggesting that the DNS role could be added after installing the AD DS role. I now get this error:

You cannot use the Add Roles Wizard to install DNS Server on a computer with Active Directory Domain Services. Instead, run the AD DS Installation Wizard (dcpromo.exe) to to install AD DS and DNS Server together.

Some other notes:

  1. I am only using the administrator account on my domain to take these actions. Naturally, the administrator account is a member of all the admin groups.

  2. There is no communication issue between any of my servers.

  3. All servers have completed all windows updates.

  4. I have added the ip address of my server2 on the zone transfer tab of the customer.local zone on server1.

My Question

  1. What steps can I take to install the DNS role on server2?
  2. Are there any other steps I should take to confirm the new domain controller has been properly added into the existing domain before I start transferring FSMO roles?
  3. Is there something I could do in the future to prevent this issue?
share|improve this question

The A delegation for this DNS server cannot be created error is not fatal, and should in fact be expected if the parent domain that it's trying to check doesn't exist (in your case, local assuming the domain you're adding to is customer.local). The error dialog asks if you want to continue; you do. See MS's documentation here.

enter image description here

Now that you're in this situation, demote the system out of being a domain controller with dcpromo.exe, then re-promote the system to a domain controller (run dcpromo again after rebooting after the demote), selecting the DNS option and ignoring the delegation warning.

share|improve this answer
I will try that now and repost. – Blackjack00 Mar 16 '13 at 21:01

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.