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My Windows 7 Ultimate x64 PC has a strange networking issue. When I resume from sleep, no web pages will load (other programs such as Hamachi VPN are also unable to locate their servers). If I use Google Chrome, it says that DNS lookups are failing. However, if I then open a command window us use NSLOOKUP to perform lookups for the web pages that just failed, the lookups appear to be working correctly. So the command prompt is able to perform lookups, while other applications such as web browsers are not.

I can clear this problem by disabling then enabling the network adapter in 'Network and Sharing Center'. After doing this, everything works again. It's a pain to have to do that each time I resume from sleep, though.

Anyone know the cause for this, or have a suggestion for how to troubleshoot it?

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Could try a different network driver maybe? Does this occur using all browsers or just with Chrome? –  jmreicha Apr 12 '12 at 18:05
Its not specific to browsers, that just happens to be the most obvious impact. For example, the Hamachi VPN client also has problems. Its an intel NIC and Intel only offers one driver. I don't even know where I'd get a different one. –  Tim Long Apr 12 '12 at 22:41
@TimLong Have you been able to resolve this issue? I started encountering the exact same behavior earlier this week after i changed DNS setup on my local area network. What i did was install Windows Server 2008 R2 as a domain controller with the DNS server role and joined some computers to the domain. The problem seems to be limited to just one computer (a member of the domain) connected to the network via an ethernet cable. LAN connections still work properly, but any WAN connections do not, even though names are resolved properly within the LAN and WAN. –  Kallja Aug 12 '12 at 17:06

4 Answers 4

Check whether you have multiple DNS servers listed. If you do, make sure all of them are valid. Having a mix of good and bad DNS servers can cause very inconsistent DNS behavior.

If you are getting the DNS server from a DHCP server, check whether the DHCP server is configured with multiple DNS and whether they are all correct.

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That's an odd situation isn't it. The point of multiple DNS servers is for redundancy, i.e. if one of them is bad, the others take over. So you're suggesting that the feature doesn't work in the presence of a bad DNS server, which renders multiple DNS servers pointless. –  Tim Long Aug 12 '12 at 21:08
The point of multiple DNS servers is only to have a fallback in the rare case that one of them is briefly inaccessible and/or to distribute the load amongst multiple systems. It is still assumed that the systems listed as DNS servers actually are DNS servers, that they will all work most of the time, and that they will not return incorrect information. When those assumptions turn out to be incorrect (whether due to servers moving or just typos), bad things can happen. –  Seth Noble Aug 13 '12 at 18:23

If you have hamachi, maybe is the culprit, after i uninstalled it all worked again, another alternative is try to enable and disable the hamachi network adapter

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Change the settings in advanced power profile properties so your LAN adapter doesn't go to sleep/power down.

This can be disabled regardless of your network adapter.

Source: Microsoft Technet

Configuring power management using the user interface

To turn power management features on or off

  1. Open Network and Sharing Center (click the Start button, type Network and Sharing in the Start Search box, and press Enter).

  2. Click the Change adapter settings link in the upper left of the navigation pane.

  3. Right click the network connection you want to enable/disable power management support on and click Properties.

  4. Click Configure.

  5. On the Power Management tab, check or clear the Allow the computer to turn off this device to save power check box.

    When checked, power management is enabled on the network adapter.

    When cleared, power management is disabled on the network adapter.

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If he has integrated NIC, nothing can be done. –  HackToHell Apr 12 '12 at 14:21
You can still change the power options for it as that's Windows based not adaptor based. See my amended answer above with Microsoft technet article. –  HaydnWVN Apr 17 '12 at 10:04

Same in Windows 8 and 8.1: After sleep the Windows DNS client does not work properly. Open the service control, look for DNS client and restart it. DNS lookup should work again without restarting the machine.

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