MAC OS
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.
How to: Set Up and Check Ethernet Settings in Mac OS 9
  1. From the Apple menu, select Control Panels, and then click to select TCP/IP.
  2. In the TCP/IP window, from the Edit menu, click to select User Mode.
  3. From the User Mode dialog box, click to select Advanced, and then click OK.
  4. In the TCP/IP window, from the Connect via drop-down menu, click to select Ethernet.
  5. From the Configure drop-down menu, click to select Using DHCP Server.
  6. Click Options.
  7. In the TCP/IP Options dialog box, ensure that only Active is selected, and then click OK.
  8. To close the TCP/IP window, click the Close box.
  9. In the Save changes to the current configuration warning dialog box, click Save.