Check your Mac for automatic IP addressing

To check that your Mac is set up to obtain and IP address automatically:

1. Click on the Apple icon (top left of your desktop) to open the Apple menu.
   
2. Select System Preferences.
3. In the System Preferences window, click on Network.
   
4. Make sure that Ethernet is highlighted in the pane on the left of the screen, and that Automatic is selected in the Location drop-down list.
   
5. Click on Advanced to display the Advanced screen, then select the TCP/IP tab.
6. Make sure that Using DHCP is ticked in the Configure IPv4 drop-down list.
   
7. Click on OK to close the window, and then click on Apply to close the Network window.

That's it. Your Mac is set up to obtain an IP address automatically.