The Mystery of the Windows Static IP That Won’t Stick

One of the interesting things about helping customers at Plugable is that we not only see a wide variety of creative uses of our products, but sometimes we also get to find the root of operating system problems.

Now I know that may sound strange. I have always been ‘that guy’ who wants to get at the true root of a problem if possible. I have spent more hours than I care to admit tracking down seemingly minor glitches in the hopes of never having to be bothered by them again.

That opportunity presented itself again recently and I thought I would share the results as they may be useful to everyone.

Some of the customers who had purchased one of our USB docking stations mentioned they were having trouble setting a static IP address in Windows. They would make the change and although everything appeared to work properly at first, the change would not stick.

That shouldn’t happen with our docks. While a driver for the Ethernet adapter does get loaded, there is nothing special about the driver that would preclude setting a static IP.

I grabbed a random test laptop and was able to duplicate this behavior. I would make the change to the network adapter in the Network Connections area of the Network and Sharing center in Windows 8.1 Pro. Although everything seemed to work fine, the change did not stick. If I went back in the settings for the Ethernet adapter, it would still be set to DHCP.

I removed the dock from the test computer and using the laptop’s built-in Ethernet adapter, I got the same results. Nothing seemed relevant in the Windows logs and no error messages were displayed.

When searching for other reports of a problem like this, the challenge is that the search terms are very general and a lot of other results pop up. However, I did find two links that finally helped me zero in on the solution:

http://support.microsoft.com/kb/937056

The Microsoft Knowledge base article referred to Windows 2000! Some steps mentioned no longer applied to Windows 8.1, but the general description seemed to fit what I was seeing.

So I decided to be daring. I made a backup of the registry (by exporting it) before making any changes and then navigated to the registry key located at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network. There I deleted the binary value called Config and restarted. This allowed me to set a static IP address and have the setting maintained as it should be.

I tested this on another machine that had exhibited the behavior and it worked there as well. Feeling confident, I emailed the fix to one of our customers who had run into the issue (with the caveat to backup the registry) and it resolved it for him as well.

Not being content with just finding the fix, I Googled the registry key to see what results I would get. It’s something I like to do to see what comes up when I search for an answer I already know. That led me to only one other result from Microsoft here:

http://blogs.technet.com/b/juanand/archive/2010/01/11/the-case-of-windows-7-network-connections-empty-folder.aspx

This blog post touts a similar fix to solve yet another range of maladies, but it doesn’t actually delve into the details of what this value records. Further searching led me to a book called Windows 2000 Server 24seven by Matthew Strebe (ISBN 978-0782126693). On Page 575 there is a reference to the Network key in general, saying it “Contains keys that create the bindings between network adapters, clients, services and transport protocols”.

There are probably more references out there that may explain what is being stored and more importantly why it can become corrupt and cause so many problems (I’ll keep digging in the hopes of find the true root), but meanwhile I hope this relatively simple fix will help people experiencing similar problems setting static IPs.

27 comments on “The Mystery of the Windows Static IP That Won’t Stick”

  1. Simon Reply

    A million thanks! I have been banging my head against the walls for the past couple of days, trying to find a solution to this problem. You sir are a life saver! Thanks again!
    Simon

    • Bob Boerner Bob Boerner Reply

      Hi Kornel, thanks for letting us know the results and glad we could be of help. One important note to anyone following this thread is that the registry key mentioned in the post has been removed in Windows 10.

      Bob

  2. Rubab Syed Reply

    I am still facing the same problem. Default gateway and DNS server settings get saved but IP address and Subnet don’t. I deleted that registry entry but no use.

      • Ted Batyi Reply

        Thank you so much! I have been experiencing this issue for around 2 years, ever since I connected more than 1 USB to Ethernet adapter (in succession, and using windows 8.1). It was driving me crazy, updating drivers for my doc, and hunting around in settings, to no avail. Not only did this explanation fix my issue, but a corrupted identifier in the registry key listed above makes enough sense to satisfy my curiosity, and explains the frustration I have been having! I love it when a fix is definitive! Thank you again for being “‘that guy’ who wants to get at the true root of a problem.” You have made my day, Sir.

  3. djraffaa Reply

    Hey, I have to thank you , i just have to, after all the discussions without any reference to any possible solution, i read yours and was rejoiced to see you helped me !!

    greetings from Belgium and again thanks a million !

    • Bob Boerner Bob Boerner Reply

      Glad we could help! When I first started researching the behavior I had trouble finding results as the behavior is very hard to define without getting unrelated information. Glad you finally found us though.

  4. Noufal Reply

    Hi, I am facing similar issue with multiple virtual servers (VMWare). There are Win2k3, 2k8 servers. They were actually working with static IP. From today morning they went unreachable and when checked I found all of them are on DHCP and getting APIPA address (Since no free IP in that IP segment). I had to assign static IP addresses to all of them to get back to working state. I have checked the group policy set on the OU, there is nothing wrong. Could not find anything in the servers’ event logs. Could you please tell me what could be the root cause here ? and how can we make sure that it will not happen again?

    Thanks

    • Bob Boerner Bob Boerner Reply

      Given that the static IPs stayed in place after you re-assigned them, it doesn’t seem like the issue you encountered is related to the behavior I describe in my post (as they would never take effect in my scenario) and you are running a very different setup in terms of the virtualized environment and server operating systems.

      Sorry we couldn’t be of more help!

  5. Jp A Reply

    I came here for the network problem, unrelated to Plugable and the fix worked, thanks so much 🙂 (I will have a look at your product while I’m here!)

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