This post is really an update of a post ( Using Your Mac As A Wireless Router ) I made back in 2007. I’ve had many emails from folks pointing out that the screenshots are not the same on their OSX. Since OSX has changed some since 2007, I will show how to do the same thing using Lion (OSX 10.7.4). (Since many of you will probably have a wireless modem/router, this may not be as useful.)
First, here’s the basic idea.
To configure internet sharing on you iMac, go into System Preferences and click on Sharing.
In the Sharing window, click next to Internet Sharing on the left. Then select Wi-Fi on right. Be sure to click on the Wi-Fi Options to set a password for your wireless network. If you don’t do this, anyone within range will be able to use your wireless network.
Also, note that you will be prompted to turn on Wi-Fi on your iMac if it is not already turned on.
Your wireless network can be identified by the name used in the Computer Name field.