Configuring Mac OS X for Internet Use
Click the Apple icon on the taskbar and select System Preferences.
Locate the Network icon under the heading Internet & Network and click it to open the Network window.
Select Automatic from the drop-down menu labeled Location.
Select Built-in Ethernet from the drop-down menu labeled
Show.
Click the TCP/IP tab and select Using DHCP from the drop-down menu labeled Configure.
Click the Apply Now button, and then close the window.