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I have a pretty new (2 weeks old) D-Link 2740B (ADSL Modem/Router). Everything was working fine until past Friday. Then, I couldn't access any website anymore. Pinging www.google.com and any other site failed. Pinging by IP adress however worked (at least for google.com) So I figured there was a DNS problem. Hence, I manually added my ISP's DNS servers in the properties dialog of my WiFi adapter (under TCP/IP). This seemed to help as I could connect to websites again.

The thing is, all of my devices had the same problem (iPhone, Notebook, Netbook...). Manually setting up the DNS IP in all my devices helped solve the problem.

Under the Status section of the router admin panel, everything seems fine. ADSL is connected. The DNS servers are recognized (the router admin panel shows the correct IP adresses for the DNS servers).

Even though I found a workaround: the day my ISP changes DNS servers, I'll have to change the IP's on every device. Hence, I would like this to stay the way it was i.e. optaining the IP automatically from the Router.

Has anyone got an idea how this could have happened. What is the problem here?

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1 Answer

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Sounds like either the DHCP or DNS server on your router has stopped functioning. Routers can sometimes reset themselves mysteriously due to a variety of electrical problems. You may want to check your configuration just in case.

If you are not getting any DNS settings at all, it may be a DHCP problem. If you are getting a DNS setting but is unable to resolve any real domains, it may be a DNS problem.

At worst case, you should not need to set all your device DNS settings but just need to set the DNS settings on your router manually and have all your devices get it via DHCP.

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Setting the DNS settings on the router may not work. About half of the routers I've tested only use those settings for their own proxy forwarder's config, and don't then put them in DHCP. – Alnitak Aug 2 '10 at 11:39
Well I do get the DNS settings from the router through DHCP. If I check the Status of my ethernet adapter, the settings are present. However, it seems that URL's can only be resolved if I manually set the DNS IP adresses on the adapter. I already tried to set the DNS manually on the router, but that didn't solve the problem. I need to set them on every single device. It's pretty weird. Might be worth noting that I already reset the router to factory defaults and completely reconfigured it. That didn't help either. – RizMan Aug 2 '10 at 11:43
I might add that I installed the latest firmware of the Router – RizMan Aug 2 '10 at 12:49
After making changes to the SOHO router, you need to reregister the DHCP of each device (e.g. rebooting them or "ipconfig /release" & then "ipconfig/renew" for Windows devices). – user48838 Aug 2 '10 at 12:52
You need to make sure that your router is configured with the correct up-stream DNS settings. Otherwise, your PC will ask the router to resolve a name that it cannot. – sybreon Aug 3 '10 at 3:26
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