DNS stands for Domain Name Server. What it does is translates IP addresses from their four octect form (192.xxx.xxx.xxx or whatever) into a name form (google.com or facebook.com).
So if your router has no way of translating the name, then you have no way of browsing the internet. What I would do is restart the router (which you've probably done). Unplug it for a couple minutes and plug it back in.
Second, go to the router configuration page. There's tutorials you can find on how to do this. There should be some sort of setting somewhere that allows you to clear your routers DHCP settings (which might in turn fix your DNS). So try that next.
If THAT doesn't work then go to the command prompt and type "ipconfig /renew" to get a new IP address (or you can unplug your ethernet cable/plug it back in).
---
class EOSERV {
Programmer | Oldbie
Open source EO Client: https://github.com/ethanmoffat/EndlessClient
};