Windows Server 2008 R2 DHCP Error 1046–not authorized

Its late last night and I am doing my usual labs and I just rebuilt my entire lab using Server Core. It’s a temporary lab for a customer POC that I will ship out tomorrow and with that I have combined AD + DNS + DHCP role in one VM. So here’s the story:

1. Successfully Installed AD and DNS, thru DCPromo /unattend:c:\DCUnnattend.txt – good.
2. Installed DHCP server role using my trusted OCsetup and it installed flawlessly.
3. Used netsh exec to load my usual DHCP configuration, same one that I have been using so far on any server install that I have for labs. Great.
4. Now its not giving any IP addresses to other client VM’s – now why?

I did some troubleshooting and found an error on the event log: Error 1046! (yea used wevtutil and viewing it thru event viewer but that’s for another story )

So what is Event 1046? TechNet says:

Event ID 1046 — DHCP General Availability
Applies To: Windows Server 2008

General availability of the Dynamic Host Configuration Protocol (DHCP) server refers to its ability to service clients. General availability depends on:

1. Proper authorization of the DHCP server
2. Presence of Active Directory Domain Services
3. Successful loading of the DHCP dynamic-link libraries (DLLs)

http://technet.microsoft.com/en-us/library/cc726914(WS.10).aspx

Wait I say to myself, isn’t this server core installation is also the AD Server of this domain? Because I know for a fact that if DHCP role is installed in a computer running the AD also, it does not have to be Authorized!

Okay, lets authorize it via CMD using this:

netsh dhcp server serverID initiate auth

or

netsh dhcp server initiate auth

Oh this will be a long night. So saved the server VM, snapshot, shutdown and then I tried it again now using a template that is not from Core (Windows Server 2008 R2 Full + AD + DNS installed from WDS, another story for later). Tried same steps and there, Then me going to the DHCP snap-in on the server manager, I confirmed that the DHCP server still appears unauthorized. Out of desperation, I Restarted my server and while doing so reading this: http://support.microsoft.com/kb/279908 Not very helpful though. Ok out of frustration, I authorized my DHCP on the MMC Snap-in and everything works fine!

Having that, I suspect I am using the wrong command to initiate the authorization. Okay going back to basics, as one of my very very dark mentor before when I was still on the ISP business “RTFM”!

So going to http://technet.microsoft.com/en-us/library/dd379483(WS.10).aspx

Wait, what?! Nah, lets see the complete manual of netsh dhcp here: http://technet.microsoft.com/en-us/library/bb490941.aspx

So lets try it out, shut down the Server Fulls and restored the Server Core VM’s fired up this command:

Netsh DCHP add server <fqdn> 192.168.1.2

and it works, its alive! its alive!

Okay lesson learned, if you are installing DHCP role with ADDS + DNS role, make sure that you add your fqdn and ip to the list of authorized servers in active directory. Snap-in authorization does this for us (I think) but if you are now using and adopting Server Core for the entire enterprise make sure that you fire up that command. Thus a new entry in my step-by-step commands on deploying Windows Server.

Now back to my servers! Cheers! And oh Good morning!

Advertisements