Yosemite keeps dropping WiFI connectivity

Solution 1:

This isn't a solution, and it isn't a definitive answer, but WiFi/Bluetooth issues have been reported by many users (including yours truly) of OS X Yosemite. Apple is reportedly working on a fix, which may or may not help all of these users.

Solution 2:

I fixed this issue on my Early 2013 MBP on 10.10.4 by doing the following (lots of other stuff was tried first).

• Disable WiFi
• Open Finder
• Press Cmd+Shft+G to go to the folder /Library/Preferences/SystemConfiguration/
• Delete (or move) the following files:
  • com.apple.airport.preferences.plist
  • NetworkInterfaces.plist
  • preferences.plist
• Restart your computer
• Re-enable WiFi