Q: Built-in ethernet vanished
I've been using built-in ethernet since forever, including the last 2-3 weeks clean installed El Capitan without problems. Today, inexplicably while working all of a sudden I'm not connected to the Internet. Network panel says the cable isn't connected, and the usual troubleshooting ensues. I've deleted all connections in Network panel, and network items from /Library/Preferences and rebooted multiple times and now in Network there isn't even an ethernet interface. System Information > Network only shows: Bluetooth PAN, FireWire, Thunderbolt Bridge, and Wi-Fi. No ethernet.
OK so I boot a live image of Fedora Linux, it sees and uses the ethernet connection just fine. So the hardware is clearly OK, it looks like the OS has somehow face planted.
MacBook Pro (15-inch Early 2011), OS X El Capitan (10.11.3)
Posted on Feb 26, 2016 6:29 PM
I *just* hit this after rebooting.
So apparently the version of the kernel extension for the built-in ethernet driver (AppleBCM5701Ethernet.ext) in OS X 10.11.3 has been added to the blacklist by Apple (AppleKextExcludeList.kext). Specifically versions lower than 10.2.0 have been blacklisted and version 10.1.12 is the one included in OS X 10.11.3.
The blacklist is dynamically pulled by OS X (it's not part of a system update) and I'm not sure what the trigger is exactly. The mod date on the bad AppleKextExcludeList.kext for me was Feb 24. The "good" one is from Nov 12.
I fixed this (probably temporarily) by doing the following:
- Get the old AppleKextExcludeList.kext from Time Machine Backup and put it somewhere on your hard drive. OS X won't allow you to overwrite it when booted normally.
- Boot into Recovery mode and overwrite the new /Volumes/<your boot volume>/System/Library/Extensions/AppleKextExcludeList.kext with the old.
- Purge your kext cache. (kextcache -invalidate /Volumes/<your boot volume>)
- Reboot back into normal OS X.
If and when OS X pulls the newer AppleKextExcludeList.kext, we'll be back to square one. Hopefully Apple will realize the mistake here soon.
Posted on Feb 26, 2016 8:40 PM


