OSX Internet Sharing

Updated 28-Jun-2024

For when your wifi breaks down and all you have is an ethernet port on your DSL, and a Mac Mini. Not so bad, but it does keep the fan running and eat up the processor. Good for short term (ship out the broken wifi router, get replacement).

Limitations of Internet Sharing on OSX

  • Only one Wifi frequency/channel (even though the Mac Mini can do 2.4ghz and 5ghz, one can only choose a single channel to use).
  • 20mhz only recommended, though it is not clear where one would change this in any case, likely hacking the registry. However, it may be that one doesn't want 40mhz, certainly not in a wifi-saturated area (such as most urban places). I can say that ALL my neighbor networks are set to 40mhz, which is ridiculous.

Configuration of Internet Sharing on OSX

  • Turn off old wifi (if using the same network name/password) on all devices
  • Plug in Ethernet to Mac Mini
  • Turn off Wifi
  • Hold down the Option button and click the Wifi button (at top of screen)
    • Select Open Wireless Diagnostics
  • From the Window drop-down menu, select Scan
    • See the other Wifi networks and their channels
    • Repeat the same at the location where connecting devices generally are (e.g., different rooms of a house or office)
    • Gnash teeth and decide on a channel (1, 6, 11, or one of the 5ghz -- 36, 40, etc.)
  • Go to Sharing, Internet Sharing
    • Highlight Internet Sharing, then Wifi, then click on the Wi-Fi Options button
    • Put in the Name, Encryption Type, Password and Channel, click OK
    • Click the Internet Sharing checkbox

If a client can't connect, then have them forget the network and re-enter the password.