You’ll need to first head into the System Preferences… or by clicking the icon on the dock or by clicking the Apple Icon and selecting it from the list.
Double-click the Network icon.
You’ll want to select your network card on the left—you’ll see in my example that I’ve got an AirPort card—and then select the Advanced button near the bottom right corner.
Once you’re there, switch over to the DNS tab, and you can start adding in DNS entries into the list. If you see entries that are grayed out, just ignore them, and click the + symbol at the bottom to add new ones.
Use the following suggested server addresses to have a good connection. Use Open DNS instead which has lots of extra features:
That’s pretty much all there is to it. When you’ve finished, click OK.
Now you may surf the web with extra quality performance.