I’m sure you have had that question before or seen it before. It is a popular question. And of course as everyone knows or at least finds out (possibly after much painful troubleshooting) is that it is the DHCP Client Service that registers your dynamic DNS updates. And when you learn that you say, but my servers aren’t using DHCP so that can’t be right… Doesn’t matter, the DHCP Client is registering the names in DNS for you… So don’t shut it off unless you don’t want your servers magically registering themselves…
That is what we have been learning and possibly relearning and recalling every time that question has been asked since Windows 2000 first went RTM. You may have forgotten it after you first heard it in class or from a casual conversation or saw it on an internet post but the first time you can’t resolve a server to name and track it down to the fact that someone disabled the DHCP Client Service because “the server wasn’t and wouldn’t ever use DHCP” you will not forget again. Right?
Well get ready to forget that piece of trivia. Microsoft was sneaky and changed the DNS Registration functionality from the DHCP Client Service to the DNS Client Service… WHOA! This change from what I understand started in Windows Vista. I don’t do much with client OSes so never ran into it. But I can absolutely confirm that this functionality is in Windows Server 2008. I glanced through the Source Code for Windows Server 2008 for the dynamic updates and performed about 30 minutes of testing with WireShark and it absolutely is moved into the DNS Client Service.
Now I admit, I may be a little behind the curve and some of you are almost certainly going to say, whoa joe… you ARE behind the curve… But I felt I would share this info because I just learned it and when I looked around I saw some confusing internet posts on the topic.
One MSFT document I saw said that sometimes the DNS Client Service does the registration, sometimes the DHCP Client Service does the registration. When I looked at the source code, that didn’t seem to be the case, also my testing didn’t seem to bear that out. Even if I was using DHCP for the server, if I disabled the DNS Client Service and, obviously, had the DHCP Client running fine, it wasn’t registering its name at all. IPCONFIG/REGISTERDNS absolutely used the DNS Client Service as well.
I updated the Wikipedia article on Microsoft DNS to reflect this change in functionality.
joe
Good to know!