Hello World! -An Introduction-
Fixing Mac OS X Lion (10.7) Network & Internet Sharing... Oh yeah!
When I first got Mac OS X Lion running on my MacBook, I went through every single "new feature", and everything worked smoothly. But when I was asked if I could share my ethernet connection through an ad-hoc network, that's where I found a problem. Internet sharing for me is crucial because I have an ethernet connection and I'm so cheap and stingy to buy a router. Therefore, finding a solution to have a wireless access point on my house with my laptop was magical. Previously, I had shared my internet connection through an ad-hoc network using Windows Vista (believe it or not), Windows 7, and Mac OS X Snow Leopard. They all worked flawlessly (though changing adapter settings in Windows because it magically changed permissions by itself was a pain), and me and everyone at my house were happy. So a couple of days back, when I upgraded to Lion, I noticed how creating networks and internet sharing were not working anymore. I was really sad. I honestly felt ripped off. I then began searching forums and exhaustively checked every single prompt on the Apple Support Discussions board, but found no answer. I was desperate, and when I had lost all hope (and thought of waiting for a Lion update), I found an interesting quote on a forum somewhere on the web. And thanks to whoever wrote it, I revealed the key to make it work! And here's how:
How To: Fix Mac OS X Lion (10.7) Network & Internet Sharing
Step 1: Open your System Preferences, which should be located on your dock or on your Applications folder.
Step 2: Click your "Sharing" folder under "Internet & Wireless".
Step 3: Make sure "Share your connection from:" -> "Ethernet" is selected (it is the fourth choice on the dropbox), and "To computers using:" -> "Wi-Fi".
Step 4: Click on the "Wi-Fi Options..." button.
Step 5: Notice how the Network Name uses your computer's name. This is because the network driver is pointing at the old Airport utility (on OS X Snow Leopard and older), and to be able to configure it to the new "Wi-Fi" scheme, you need to rename the network to something short like: "SM MBP".
Step 6: After you have changed the name of the network, click "OK", and you will be prompted with the System Preferences Change window:
Step 7: Type in your password, and click "OK". This will now point the network driver to the new Wi-Fi utility.
How to know it really worked: After you've done this, the arrow-pointing-up icon on your Wi-Fi status icon will show up. This also works with creating a network directly by clicking your Wi-Fi status icon -> "Create network". The prompt is similar to the "Wi-Fi Options" above. Rename the network to a shorter name, and voila! Your Wi-Fi statusbar icon should be replaced with the computer icon.
Update #1: Mac OS X Lion 10.7.1 does not fix the networking issues. You may use the steps on this guide to get it working again after updating.
Update #2: Networks created following the steps on this guide will be discoverable and usable by any Wi-Fi enabled device. I tested it with my Nintendo Wii console and it worked flawlessly. (It's weird since I had previously done this with Snow Leopard with no success at all, but it works now :')).
Update #3: Mac OS X Lion 10.7.2 is out and still no fix for networking issues. This guide is still useful.
Update #4: This was supposed to be my first Newsstand app publication, but for the time being, it'll be a public release through a public web server. Scroll to page #7 for the OS X Lion networking fix extended guide. Hope it helps! http://dl.dropbox.com/u/40383609/Creative_September_NetworkFixLion.pdf
Update #5: This will work on OS X Mountain Lion as well. :)