Enable Internet Sharing in Mac OS X to Turn Your Mac Into a Wireless Router

Did you know you can turn your Mac into a wireless access point by using Internet Sharing? Internet Sharing works for both Mac OS X 10.6 and Mac OS X 10.7 Lion, and with internet sharing enabled, your internet connected Mac will broadcast a wifi signal that can be used by another Mac, PC, iPad, iPhone, or whatever else you need to get online from.
Here are situations where Internet Sharing is particularly useful:
- You don’t own a wireless router – no problem, let the Mac become one
- There is only a wired internet connection (ethernet) available, and you need to get a wireless-only device online, like an iPad or MacBook Air
- You’re at a location that charges internet access per device, rather than a flat rate for all devices, this is fairly common at hotels and airports
- Skirt the connected device limitations of Personal Hotspot (iOS) and Internet Tethering from mobile phones
Hotels in particular have a bad habit of charging customers a per device fee rather than a single per room cost for internet access, using Internet Sharing gets around that greatly inflated expense.
The setup we are going to use in this example is as follows: Wired internet connection -> Mac -> Other Devices, here’s a simple diagram to demonstrate this:

It’s easy to set up, let’s get started.
How to Share Internet from a Mac to Other Computers & Devices
We’ll walk you through the process of setting up a secured wireless access point, broadcast from an internet connected Mac to be shared with other Macs, PC’s, or iOS devices.
- Connect the ethernet cable to the Mac
- Launch “System Preferences” from the Apple menu and click on “Sharing”
- Click on “Internet Sharing” from the left menu
- Select the pull-down menu next to “Share your connection from:” and choose “Ethernet”
- Alongside “To computers using:” check the box next to “Wi-Fi” or “AirPort” (name depends on OS X 10.7 vs 10.6)
- Next click on “Wi-Fi Options” and name the network, and then click to enable security/encryption, and then type in a WEP key as the wireless password
- Click “OK” and confirm that you want to start internet sharing



You’re done. Your Mac is now broadcasting a wireless signal that can be picked up by any other wi-fi enabled devices. Connecting to the Mac’s shared internet connection is now the same as connecting to any other wireless network, find the wifi access point name you set, enter the password, and you’re online. The network is relatively secure thanks to the WEP password you set, if you forgot that password you just have to disable security and re-enable it to set a new one.
If you’re a perfectionist, you could then run the Wi-Fi Diagnostics tool and get the optimal signal for the network, but in a brief hotel or airport situation, the the devices will be close enough together that this won’t matter much.

The problem is that the Mac only provides a WEP connection which means the password is easily hacked.
Investing in an Airport Express will provide better security. Another good solution is to use one of the VPN services out there. This will allow you to connect to the internet over an unsecured connection, like your Mac on WEP, and still be secure.
Great trick, didn’t know you could do this!
An oldie but a goodie Tip. Been doing this for years now
It doesn’t work for me. I set it up just like you said, with my MacBook connected to ethernet. All went well until I tried to use it. Found the name I’d set up on my Android phone, selected it, entered the WEP password, phone said “obtaining IP address” for a few minutes, and then went to “Disabled WEP secured”, and never connected. Tried several times…same result. Nice idea, I would love to use it at home, but I can’t make it work, and I don’t know why.
Try setting it without WEP encryption or by using a different encryption strength. Figures that if any device was to have a problem though, it’s an Android trying to connect to an Apple… LOL.
No, it’s an Android trying to connect THROUGH an Apple.
Tried it both ways, first with 40-bit WEP, then wide open. Same result – first says “obtaining IP address” then “Disabled”. Oh well…
I’d like to share from my connection airport to airport. Is there a way to create a virtual adapter a la windows 7?
I’d like to share my connection from airport to airport. Is there a way to create a virtual adapter a la windows 7?
You are actually encouraging people to setup WEPs!? Come on guys, that is insane! The internet sharing on OSX, even though it could be really useful if it supported WPA2, should NEVER be used and should be considered obsolete. Nobody should be using WEPs in 2012.
Anyone actually got this working on lion?
Yes I am doing it with Lion
mine doesn’t actually share the connection? please contact me on twitter to help me: @Llionv
I tried this at work – but when I start the WiFi-Diagnosis-Tool I can see that my set up network has no signal… I tried it with WEP and without (just to check if this causes the failure).
The Channel (10, I tried others as well) isn’t used by any other network around here (my early 2011 iMac has a AirPort Extreme-Card in it) – anyone any ideas why there’s no signal?
Does not work for me.
“Wi-fi has the self assigned IP address 169.x.x.x and will not be able to connect to the Internet.”
“Network name: Internet Sharing: On”
My ethernet connection works ok. Wi-fi devices still can’t use it.
It should be noted that enabling Internet Sharing this way is likely to cause one’s computer to fail to go to sleep.
is there any way to change the WEP to WPA2?
And how can I share my internet using N wifi, i can create only G adhoc ;[