How to: Verify TCP/IP Network Settings in Mac OS X
  1. On the Apple menu, click System Preferences….
  2. From the System Preferences window, click Network.
  3. From the Network window, on the Show drop-down menu, click Built-In Ethernet.
  4. On the TCP/IP tab, from the Configure IPv4 drop-down menu, verify that Using DHCP is selected. Note:The IP Address, Subnet Mask, and Router fields will automatically update.
  5. On the PPPoE tab, verify that Connect using PPPoE is not selected.
  6. On the AppleTalk tab, verify that Make AppleTalk Active is not selected.
  7. On the Proxies tab, verify that no options are selected.
  8. On the Ethernet tab, from the Configure: drop-down menu, verify that Automatically is selected.
  9. To save the settings, click Apply Now.