Vista: TCP Window Scaling Errors - Cannot communicate with Primary DNS Server

Contributor Icon Contributed by davak Date Icon October 12, 2006  
Tag Icon Tagged: Microsoft Vista

In vista TCP Window Scaling is enabled by default. If your router does not tolerate this feature, it can cause random DNS and connection errors. This is a common cause of vista limited connection errors.


Microsoft’s Vista enables a TCP Window Scaling option by default. For most systems this is a good thing. However, if your router does not tolerate this feature, it can cause many connection areas on your network. This conflict will cause drop packets and limited connection in many circumstances.

If you try to diagnosis this problem, you may see a window that says that Windows Network Diagnostics “Cannot communicate with Primary DNS Server”

To fix this problem, you should do one of two things. First, just upgrade your router to take advantage of this new feature. Second, you can just turn off this TCP feature.

I am sure there is an easier way to turn off this TCP feature. I just don’t know it. Here is how I have been doing it:

1. Connect to your network on your troublesome vista box
2. Click on this link while your network connection is working:
res://ieframe.dll/dnserror.htm#
3. Click the link that says Diagnose Connection Problems
4. You should see something like this:

5. Click the button that says Turn off the TCP setting that is not compatible with your router.
6. Allow the repair to take place

If it works to fix your system, you should notice that your episodic connection problems disappear.

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  • Anonymous
    please help me on this problem.

    I am using Vista RTM, and i can't acces the internet because of this problem, Cannot Communicate with Primary DNS. The thing is, this version on Vista does not have the "Disable the TCP setting" option.

    PLEASE HELP ME.
  • Anonymous
    I think this command should disable the scaling option via a Command Prompt:

    “netsh interface tcp set global rss=disabled”

    Hope it helps
  • Anonymous
    Hi,

    I'm having the problem you describe, intermittently. I can't change the router because we have community WiFi, thus I don't have control. I tried your "TCP" fix and it didn't correct the problem. Any other ideas?

    Regards,

    Dave.
  • cozofdeath
    Verify that the dns server is correct in your tcp/ip properties and also with nslookup.
  • Anonymous
    I am getting the "cannot communicate with primary dns server" and i cannot connect to the internet. I tried the "netsh interface tcp set global rss=disabled" in command promt and it said - Set global command failed on IPv4 The requested operation requires elevation.

    What do I do?
    Please Help :S
  • Anonymous
    Haven't seen reference to this specific issue except on your site. The fix has seemed to make it worse.

    I have Windows Vista Home Premium
    Verizon Fios 15mB/15mB
    uTorrent
    IE 7

    In uTorrent I get the following error when the BT tries to access a tracker.

    An attempt was made to access a socket in a way forbidden by its access permissions

    Which apparantly uses http. The Torrent files continue uninterrupted. Switching to open or new windows in IE7 creates the following error message:

    res://ieframe.dll/dnserror.htm#

    Correcting the problem through IE results in resetting the network connection. Doesn't work.

    Any Ideas?

    Thanks=
  • blaz
    i can olny send msg to microsoftu ;/
  • kameron
    the link shown did not work for me but i wait for the tcp error to come up to turn off tcp settings.
  • Rahul
    In the TCP/IP settings, I changed the DNS IP addresses. I got the correct ones from my other laptop. (Do ipconfig /all in the cmd prompt) Looks like the DNS addresses got messed up on my vista system
  • Shashank
    I had set up access restrictions on my router to allow internet through a specific MAC address for my laptop. With my new Vista laptop giving this problem initially I had forgotten that. Now after adding new MAC address I am back on internet. Hope this helps someone.
  • Shashank
    I had set up access restrictions on my router to allow internet through a specific MAC address for my laptop. With my new Vista laptop giving this problem initially I had forgotten that. Now after adding new MAC address I am back on internet. Hope this helps someone.
  • Dirge
    TRY THIS: It worked for me:
    ---In vista (x32 bit) -probably works very similarly in vista, though i think this is more of an issue in vista.

    Before doing anything, bring up your ip settings for reference. To do this:
    -Right click command prompt in start menu-run as administrator- type: ipconfig.
    (This will display your computers and routers actual ip settings.)

    My symptoms were strange. The wifi network had no changes, and was working fine on other machines. On the vista laptop, the wifi card received the signal, and even gave access to the internet. While Google loaded with no problem, and most searches went just fine, many many sites 404ed, and would not come up, and the connection was rather weak and finicky. Also, i got the following message from my diagnosis.

    If you have a similar issue, PLEASE ATTEMPT THE FOLLOWING:

    Control panel- network and sharing center-view status (of the troubled network... usually the wireless network)- then click diagnose...

    At this point, if the problem persists, you will see the message:

    "Cannot communicate with (Primary) DNS server (IP ADDRESS). "
    "Network diagnostics pinged the remote host but did not receive a response"

    Follow several steps to solve the problem completely. First:

    Return to your -view status- window you opened earlier, and instead of clicking Diagnose, -click properties (you need administrative access)

    -Under the networking tab:
    -In the "this connection uses the following items:" list, select:
    -Internet Protocol Version 4 (TCP/Ipv4).
    -click properties
    -under General tab there are two sections, one for setting the IP and one for the DNS.
    -set the DNS to "Obtain DNS server address automatically."

    THAT SHOULD FIX YOUR PROBLEM. Click OK, and return to the status, and:
    -click Diagnose- thr problem should be resolved. If it is not:

    -select "Use the following IP address" and enter your information from the command prompt (IP address, subnet mask, and default gateway) Leave the DNS on automatic.

    Problem should be solved. If not, good luck! I highly recommend you look through windows help (aka not online, just your on-board help system from windows. That is how i figured out how to change the settings that fixed mine.
  • Raphael Barboza
    Dirge,
    Your tip saved me, but in my case, specifically, it only worked using both automatically (IP address and DNS servers). Thanks!!
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