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I have a home network with a cable modem, wireless router, several switches and powerline adapters all connected with cat5.

When web browsing, I am regularly getting DNS timeouts (1-2 every 10 minutes) and if I wait 2-3 minutes, DNS lookup will start working again. Services like Netflix where I'm connected to the same service for a long period of time are unaffected. All PCs, tablets, and phones on the network are affected.

I've set both my browsers and my router to use google's DNS (8.8.8.8 and 8.8.4.4) with no improvement in performance.

How can I trace the source of this error? How do I know if the problem is with my router or modem or my ISP so I can continue troubleshooting?

Attached is an image of my router settings.

enter image description here

Update:

Using nslookup from the command line returns

Default Server: google-public-dns-a.google.com

Address: 8.8.8.8

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  • Did you set the DNS on the router or just on your desktop/laptop? I would just connect the desktop or laptop directly to the modem. If you have the same DNS problems then you know its the modem, actually it would simply be your ISP that is having DNS problems
    – Ramhound
    Commented Dec 13, 2014 at 18:48
  • @Ramhound both. Also, my router has an option for an "advanced DNS Service" so I've tried that turned on and off (turned on it sets the DNS servers to somewhere else). The router is a Dlink DIR-655.
    – Zaralynda
    Commented Dec 13, 2014 at 18:51
  • @Ramhound oh I should have thought of that, thanks! The modem is off in another room from the rest of the equipment so I didn't think of it.
    – Zaralynda
    Commented Dec 13, 2014 at 18:52
  • As for the DNS problem you seem to have, the reason it goes in and out, is your using Google's DNS server and your ISP's which are likely your primary and secondary. Its only when those timeout does Google's get involved. A screenshot of that page of the interface would be helpfu. Just upload it to an image host and I will place it in the question itself.
    – Ramhound
    Commented Dec 13, 2014 at 19:01
  • I want the settings on the router. Your browsers settings are not important. I want to confirm the router not just a computer is set to use the Google DNS servers.
    – Ramhound
    Commented Dec 13, 2014 at 19:04

1 Answer 1

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The problem you are experiencing is most likely related to your router itself.

I have seen situations with DLink routers that lose their DNS connectivity and either recover after a period of time, or immediately after a reboot.

Check the machine that you are browsing from. In that you will most likely see that it is using the router as it's DNS, whereas if you set the DNS used by your client machine (browser machine) to google, rather than going via the router your problem will be fixed.

This however is not ideal when using a laptop that may connect to different routers at different periods.

To test this theorom related to the router, open a cmd window and use nslookup to test.

nslookup
> server
Default server: your router ip address
> someurl.somedomain
#### Timeout error message
> server 8.8.8.8
> someurl.somedomain
Valid response

Reboot the router and try the same test. The first timeout message should not appear. This would indicate that the DLink router is not forwarding DNS requests as required.

I currently have a defect lodged with DLink support regarding this intermittent issue with DLink routers.

So as a short term fix, set the DNS settings for your browser client to be something other than the router.

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  • using nslookup returns google's servers as the default (see full response in question)
    – Zaralynda
    Commented Dec 16, 2014 at 22:21
  • And entering a lookup address works?
    – sweetfa
    Commented Dec 16, 2014 at 23:20
  • yes, but I haven't been able to catch it when the error is happening
    – Zaralynda
    Commented Dec 17, 2014 at 0:55

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