Ask a question


How can we help you today?

Ask Question
Manage notifications
Subscribe to this question
Rodolfo Terron

The Authorization of DHCP failed with Error 20079

Good morning. I am Migrating another SBS2011 system to Server 2016 Std. I am on Section 9 (Migrate DHCP settings) Step 28 of the guide. After installing the DHCP server and configuring it and importing the settings from my old server, it showed me a 169... address in the DHCP console. It seemed to have some of the DHCP settings, but not all of them. I tried restarting DHCP on the new server- no luck. I then tried uninstalling DHCP from the new server and rebooting and when I reinstalled DHCP I noticed that after "configuring" it- it gave the following message "Authorizing DHCP Server Failed. The Authorization of DHCP failed with Error 20079. The specified servers are already present in the directory service..."
Not sure how to correct this. Any help would be greatly appreciated. Thanks. 
 

asked04/28/2018 14:57
11398 views
Add Comment
Mariette Knap

Microsoft MVP

Hello Rodolfo,

Uninstall DHCP from both servers and reboot both. After that install DHCP on the new server and make sure you check the Network Adapter of your new server, it must NOT show that 169 address. I don't know why this sometimes happens but probably the new server did have something left over from the time it got a 169.x.x.x that was assigned by Windows APIPA.

If this did not work let me know and we will get this fixed another way by using ADSIEdit.

Rodolfo Terron

Uninstalled DHCP role from both servers, rebooted, made sure only one NIC was enabled on new server. That NIC has a static IP and is pointed to the old server for DNS1, itself fro DNS2. Reinstalled DHCP role and got the same 20079 error when configuring it. Let me know if there is anything else I can try. Thanks.

replied 04/28/2018 16:14
Mariette Knap

Microsoft MVP

Oh bummer. Can I help you tomorrow in a remote session? I would really like to see this

replied 04/28/2018 16:21
Rodolfo Terron

Hi Mariette. Ok, just let me know when is convenient for you. I sent you the TV ID\pass for tomorrow. Thanks again.

replied 04/28/2018 17:04
Reply
Last Activity 03/20/2019 15:41

1 Answer(s)

  • Mariette Knap

    Microsoft MVP

    We had some really odd behavior because the old server was authorized at 127.0.0.1 in the Active Directory and therefore blocking authorization on the new server. With the following Powershell

    # Lists the authorized DHCP servers in the AD
Get-DhcpServerInDC

# Removes a specific authorized DHCP server
Remove-DhcpServerInDC -DnsName "oldservername" -IPAddress 127.0.0.1

    we were able to remove the bad DHCP server in the AD.

    answered 04/29/2018 11:57
    Add Comment
    Rodolfo Terron

    Yes, that worked like a charm. Thank you again for your prompt help. Much appreciated. Feel better. 

    Reply
    replied 04/30/2018 11:48
Add an Answer