Networks

Ask something
Question Locked

Why does our preferred DNS Server setting keep reverting?

0 helpful
8 replies

by jenna_a 3 views

Closed to new repliesThis discussion is closed. It stays readable, but it takes no new replies.
We have a domain running Windows Server 2012 Essentials on the server and Windows 7 on each client computer. Client computers are set up with static IP addresses, and with the Preferred DNS server set to x.x.x.254, which is the IP address of our modem. When these settings are intact, everything works beautifully. However, upon restart, the client computers' Preferred DNS Server keeps resetting to x.x.x.5. which is the IP address of our server. When that happens, internet connectivity becomes spotty or nonexistent. Taking 30 seconds to load google.com or just giving page load failures. I cannot figure out why the Preferred DNS Server keeps resetting to our server's address. I have also tried putting in Google's DNS server on the client computers but it's still significantly laggy over the proper x.x.x.254 setup. I have tried to figure out if there's some sort of DHCP problem on the server, but I can't find the setting in 2012 Essentials, and honestly, I'm not entirely sure what to look for if I did find it. When a computer is plugged into our wired network for the first time, it always shows an IP conflict until we assign one manually. I don't know if that's related to DNS problem or not, but I figured the more info the better, right? (FYI, wireless is handled via DCHP from the router and is on a completely different range than the wired network. Only the wired network is giving us problems.)

8 replies

by robo_dev

In the settings on each PC, I assume you have the DNS server set statically as well as the address? If not, the PC will attempt to set a DNS server on it's own with unpredictable results.

Keep in mind there are lots of viruses that muck with DNS, such as the DNS changer virus.

The only way that PCs are getting DNS from the server is if DHCP is enabled in the server; if you're setting static IP addresses, then you should disable DHCP on your server unless you need it for something else. Have not worked with Server 2012, but typically simply stopping and disabling the DHCP service takes out DHCP.

Part of what complicates things is cache. Both the server and clients cache their DNS settings, so there are command-line commands to flush the DNS cache on the server (and in the clients). ipconfig /flushdns Cached DNS is why you get duplicate IP errors.

by jherrick

Your server is probably a domain controller in an Active Directory domain. The workstations in that domain should use the server as their primary (and only) DNS Server, by design. You can set the forwarder entries (in the DNS Server configuration) of the server to point at the router or another set of upstream DNS servers (typically provided by your ISP).

by bill.gilliss

Here is how I finally solved the problem with LAN/wireless conflicts on Windows 7 workstations on a small Windows Server 2012 Essentials domain, where the DNS address of the NIC on the server on the wired local LAN kept overriding the (different) DNS setting of the wireless cards on the workstations (used for internet acccess) every time a workstation restarted.

It turns out that the "Connect this Computer to the Network" routine you run on each workstation when setting up the domain (http://servername/connect) installs a service called Windows Server LAN Configuration, that basically tells each workstation to get its LAN settings from the server. Since I didn't *want* the workstations to pick up these settings, I disabled the service on each workstation, and both cards now work as desired.

(Incidentally, the few workstations that were not having the problem were ones that for some reason -- hung installation routine?? -- did not get the service installed.)

This is for a small 20-PC domain where I have all the wired LAN IP addresses set as static IP's, so I can't say how this will affect a system that requires more flexibility.

1) On each workstation, right-click Computer
Manage
Services and Applications
Services
Windows Server LAN Configuration
Disable

2) Set wireless DNS settings correctly

3) Restart

4) Yes!!!

by computerprosil

Thank you to Bill G for saving me a lot more aggravation! FINALLY, my DNS stays on automatic!!

by scott47

I used Bill's solution with great results when using Essentials 2012 but the service that he disabled no longer exists with Server Essentials 2012 R2.

I found another solution online that I'm sharing here in case other poor souls are searching for a way to unhook Server 2012 from overriding the default DNS addresses. I used this solution on Windows 8.1 and it worked perfectly. Please note, I did not have anything to do with writing the solution, and I'm only sharing it for others benefit.

Here's the page:
http://www.tinkertry.com/how-to-make-windows-server-2012-r2-essentials-client-connector-install-behave-just-like-windows-home-server/

by tinkererguy

scott47:
So kind of you to share my article, glad it has helped others!
It was fun figuring it out, and even more fun sharing it!
Let's hope Microsoft makes it all even easier in future releases.
-Paul Braren, aka "tinkererguy" from TinkerTry.com

This discussion is closed to new replies.