Google has announced their own public DNS server which will be available for everyone on the Internet. Google’s main goal is to increase the speed of web browsing for users and is a good alternative to OpenDNS.
I have faced many problems with STC‘s DNS servers and many Saudi users are complaining from Go‘s DNS as well. So it’s a good idea to change the DNS server in your Mac and AirPort devices (AirPort Extreme, AirPort Express, Time Capsule).
How to setup Google Public DNS on a Mac
Launch System Preferences, choose Network, choose the connection you are using for the internet (WiFi is usually AirPort, LAN is usually Ethernet). Click Advanced. Click the DNS tab. Remove older DNS servers from the left if there is any (press the minus button). Add 18.104.22.168 and 22.214.171.124 by pressing the plus button. Press OK then Apply.
How to setup Google Public DNS on AirPort
Launch AirPort Utility, choose the device you want to change the settings of. Click Manual Setup. You might need to enter the password here. Click Internet tab. Change the DNS Server(s) fields, enter 126.96.36.199 and 188.8.131.52. Click Update. Click Continue and the device will restart with the new settings.
Arabic version on SaudiMac.net.