DNS look up fails

Question

I turned my router off for the weekend. When I got back today I couldn't access any sites. Usually I access my router by typing in speedtouch.LAN but today I had to use its IP address. I pinged both DNS servers and the primary succeeded while the secondary failed. So I changed them to Google DNS (8.8.8.8 and 8.8.4.4) and still I couldn't access the Internet like usual. I looked up Google home page's IP address on my phone and entered the IP address on my MacBook and I got to Google so I know it is only DNS I'm having a problem with.

I then tried a different router (also a speedtouch, with the same software) and again had the exact same issue.

So on my Windows PC I edited the connection so that it didn't get the DNS server automatically but rather forced it to 8.8.8.8 and 8.8.4.4. And suddenly it worked on that computer only.

Setting the DNS servers in network settings on my MacBook, however, didn't work. Connecting to the network on my iPhone works great. No fiddling with DNS settings on the phone, it just works as normal.

I really do not want to have to set the DNS servers manually on all devices. Why is it that the two routers have had the same problem with DNS and how can I fix it?

Answer 1

I would guess that you're using DHCP to hand out dynamic IP addresses, and it sounds like the DNS values the computer is receiving aren't working. From a command window, run ipconfig /all to see the settings.

One option is to configure the router to use Google DNS (or opendns) rather than the values provided to the router from the ISP. You can then renew the DHCP lease, and you should be good to go.