If you want to set up a shared connection to the Internet using hardware, you must collect the modem, cables and router. Not only does using a dedicated piece of hardware save a Mac on your network from the task of hosting the shared connection, but it also prevents you from having to have more than one Ethernet connection on one computer if you’re using a cable/DSL modem to access the Internet. You can connect your devices to share devices over the Internet using either a cable/DSL router with a built-in Ethernet switch or a cable/DSL router with a standalone Ethernet switch, where you’ll need to use AirPort or AirPort Extreme.
If you choose to purchase a cable/DSL router that has a built-in Ethernet switch, you can simply connect all of your computers on the LAN to the built-in switch. However, if you buy a Cable/DSL router that has only one LAN connection, as with older versions of the AirPort Base Station, you must connect the single LAN connection to an external hub or switch in order to get all the computers on the same network .
This indicates wired Ethernet. Wireless connections do not require a port in a router or base station.
Regardless of whether you use a hardware or software method to share your Internet connection, all computers on your LAN—except for the one doing the sharing, if you use software sharing—must be configured to obtain their IP address automatically from Through an old friend, Dynamic Host Configuration Protocol (DHCP). Although setting up your other devices with DHCP is not a requirement, it is recommended unless you understand the IP addressing system that your cable/DSL router requires and are willing to set up the addresses manually. You need to follow the instructions that came with your cable/DSL router or software that you purchase for detailed information on how to configure this.