I'm seeking assistance for a problem I believe lies in my DIR-600 router.
Hardware version: B5
Firmware: 2.17 (updated to the latest)
Region: Germany
Internet: Unitymedia cable modem
Whether surfing on my Android phone, iPad, or Windows 7 laptop, my internet will occasionally stop working. When I run the diagnostic on Windows 7, the response is always "The DNS server is not responding."
The same error always occurs whether the laptop is connected ethernet only (with WIFI disabled) to the router, or WIFI only. Thus I think the problem is not the wireless. The internet cuts out for all devices and not just one, therefore it is not merely one device.
If I run ethernet directly out of the cable modem into the laptop, this problem never occurs. Thus, I believe the problem lies in the router.
Every time, the problem is temporarily solved by resetting the power on the cable modem by cycling the power. Resetting the router never makes a difference. Once the modem is reset, internet access is restored- for a month, a week, an hour. Lately more like an hour. Then it's out again. This has been a problem since I first started using this service with this router two years, ago, but now disconnections are so frequent I must solve the problem, and it's not the ISP.
I've tried changing the primary DNS servers to GoogleDNS or OpenDNS. Same problem occurs. I've tried changing various settings within the DIR-600, and a factory reset. Same problem occurs. While changing some router settings, I succeeded in getting slightly different error messages from the Windows troubleshooter: "Windows can't communicate with the device or resource (primary DNS server.)"
Any help would be much appreciated. Thanks!