Make a secure ad hoc wireless control network

At some point along the way (I can’t remember when…), Apple removed authentication security from the ad hoc network function “Create a network…” in the Wi-Fi setup. I use ad hoc networks to link up mobile devices to Macs running Max, QLab, Isadora, etc, and not being able to lock up the network is a real drag, and security hole. Here’s a better method.

Setup

First, go to System Preferences>Sharing. Uncheck “Internet Sharing’ if it is checked. Then, enter the following in Terminal:

You can alter the IP address to your liking. You will use it in a few more steps.

Configuration

  • Go to System Preferences>Network and configure the newly created ‘Loopback’ network device to match the IP and subnet above, setting the ‘Configure IPv4’ menu to ‘Manually.”
  • After setting up ‘Loopback,’ go to System Preferences>Sharing. Click ‘Internet Sharing’ from the list at left. In the resulting menu to the right, change ‘Share your connection from’ to ‘Loopback’
Internet Sharing configuration
  • Under ‘To computers using’ check ‘Wi-Fi’
  • Click ‘Wi-Fi options…’ and set a name, password and channel for the new wireless network.
WiFi Options configuration
  • Click OK to return to System Preferences>Sharing. Check the ‘Internet Sharing’ box to enable the new secure network.