Internet Sharing on OS X

Saturday, November 24, 2007 03:56 AM

I've been using Parallels a lot lately. Anyways the most annoying thing about OS X Internet Sharing is the default network address space is set to 192.168.2.0/24. The big issue with that address space is that if you're on a network that uses that address space and you want to use your parallels (utilizing host-only networking) with internet sharing you are immediately screwed. Dear Apple why is there no UI for this? I've spent a fair amount of time researching how to get into the innards of OS X to reconfigure this default DHCP address space range. After "googling" around for what seemed like a lifetime, I found this man page for InternetSharing.To fix the glitch:

  1. Make sure that internet sharing is off in System Preferences->Internet & Network -> Sharing.
  2. Edit /Library/Preferences/SystemConfiguration/com.apple.nat.plist, and add the following nodes to the "Nat" node.SharingNetworkNumberStart192.168.100.0
  3. I could not figure out how to make the changes to com.apple.nat.plist persist, so I restarted OS X. Instead of restarting the OS, I should have restarted com.apple.InternetSharing via launchd.

Finally:After the restart, and enabling Internet Sharing I was finally receiving an IP address from the newly configured address space.