Mac OS X Airport Internet Sharing with Ubuntu with WEP

Have you ever tried Internet Sharing in Mac OS X for Ubuntu clients, using WEP? Did it work for you at the very first time? If not this post is for you… :)

I own a 3G HSDPA internet card for my Macbook Pro and I need to share my connection to my Ubuntu laptop.

Easy, you goto System Preferences, select Sharing icon and click “Internet Sharing” for computers using Airport. If you don’t use WEP to encrypt your Wireless connection you’ll have one open Access Point to the world. So I need to use WEP to secure my network since Mac OS X Leopard does not create wireless networks with encryption other than WEP… damn!

System Preferences

Ok, lets create the wireless network and place a password. The problem with this “password” is that when you try to use Ubuntu NetworkManager it simply doesn’t work. Still don’t know why, but I believe it’s a Mac OS X problem, since my Windows box doesn’t work either.

So instead of typing a simple password, use a hexadecimal WEP key. Let’s consider you choose a WEP key in hexadecimal form 1234567890. You need to create your network in Mac OS X with the following key: $1234567890

The “$” tells Mac OS X the key is in hexadecimal and not a simple pass phrase. Hexadecimal keys must be 10 chars wide for 40bit WEP or 26 chars wide for 128bit WEP.

Ubuntu NetworkManager

Now use the same key in Ubuntu and NetworkManager but without the “$“.

If everything went fine you’ll be able to share your internet connection.

Connection Established

26 thoughts on “Mac OS X Airport Internet Sharing with Ubuntu with WEP

  1. Hi,

    Your post was extremely useful. However, I was not able to get it working with the firewall switched on on my Mac.
    Do you have any idea how to resolve it? I’m just scared to switch my security off even on a Mac.

    Thanks a lot,


    braceta Reply:

    I’m without firewall too… If I found out, I’ll post it.


  2. Did not help for me :(

    MY mac is connected to the net using PPP0E, would that make a difference?


    braceta Reply:

    Shouldn’t make any difference. Can you enable Internet Sharing with some device connected to your ethernet port?

    The problem might be on the Internet Sharing and not on VMWare…


  3. Also didn’t work for me initially (Ubuntu 9.10), though I got it working in the end. What seemed to solve the problem (?) was changing the network authentication in Ubuntu from ‘open system’ to ‘shared key’.
    In case you don’t know how to do this:
    – right-click wifi icon,
    – click ‘Edit Connections’,
    – click ‘Wireless’ tab,
    – select the wifi network that you created with your Mac and click ‘Edit’,
    – click the ‘Wireless Security’ tab
    – change ‘Authentication’ to ‘Shared Key’.

    Hope that helps somebody out there.


    blibla Reply:

    This tip worked for me. For a 40 bits 5 char password. Thanks.


    Amy Reply:

    Thank you so much! That fixed it.


    Brian Reply:

    Thank you! I’ve been trying to do this forever!


    Mauricio Zepeda Reply:

    Thanks man! This did the trick. I would have never found that out on my own. Using 128 WEP!


    Francisco Reply:

    This fixed my problem too!

    Thank you!!


  4. Actually, you don’t need to prefix the key on the Mac side with “$” or treat it as a numeric string. The primary issue is that the Mac needs to receive the request as a key, not as a passphrase. As it states clearly on the config screen for the Mac, you can use a 5 character key for 40 bit auth (or 13, but 5 is nominal i guess); you must use 13 characters for 128-bit auth. Other than those restrictions, you can use whatever characters you want. The odd exception to this is if you use all numeric characters, the length can be 10.


Leave a Reply

Your email address will not be published. Required fields are marked *

Captcha * Time limit is exhausted. Please reload the CAPTCHA.