Creating an Ad-hoc Wireless Network
Creating your very own wireless network using your Mac is easy. To do this, you’ll need a wired ethernet connection (or if you’re still using dial-up, you can use that as well). Simply connection using your wired option, and then open System Preferences > Sharing > Internet Sharing.
Creating an Ad-hoc Ethernet Network
Let’s say we need to do the opposite: Create an ethernet network from a wireless network. Well, your Mac can oblige in this case as well.