OS X Mountain Lion: Choose a manual IP address or use DHCP
When you set up a connection to an ISP or an Internet Protocol (IP) network, you need to provide OS X with the correct IP address to use to connect to the Internet or the network.
An IP address is a number that identifies each sender or receiver of information across the Internet or IP network. Currently, the most widely used IP protocol is IPv4 (IP version 4). IPv4 addresses are a series of numbers divided by 3 periods, and look similar to this: 126.96.36.199.
Another IP protocol, IPv6, is being adopted as more and more computers require IP addresses. IPv6 addresses are a series of numbers and letters divided by 7 colons and often look similar to this: fa80:0000:0000:0123:0203:93ee:ef5b:44a0.
Your IP address can be provided a number of ways. The most common are manual addresses you receive from your ISP and addresses you receive automatically using Dynamic Host Configuration Protocol (DHCP). If your ISP or network account uses DHCP, your computer is assigned an IP address automatically. If your ISP or network account provides your IP address manually, you need to enter the address in the Network pane of System Preferences.
- Choose Apple menu > System Preferences, and then click Network.
- Select the network port configuration for your account (such as Ethernet) in the list at the left.
- Choose Manually or Using DHCP from the Configure pop-up menu. If you choose Manually, enter the address in the IP Address field. Your ISP most likely gave you other addresses as well, such as the subnet mask, router, and Domain Name System (DNS) server address. Enter those addresses in the appropriate fields.