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   El Capitan's System Integrity Protection Broke Ethernet

   Josh Centers

   Many Mac users were baffled over the weekend when their Ethernet ports
   stopped working. Thankfully, Apple swiftly published a [1]support
   article about how to fix the problem. The culprit appears to be an
   update to OS X 10.11 El Capitan's System Integrity Protection security
   feature, which accidentally disabled the kernel extension that manages
   the Ethernet port.

   Apple pushed out a second update to the Incompatible Kernel Extension
   Configuration Data that should automatically fix the problem. But if
   the first update disabled your Ethernet port and prevented the second
   update from installing, follow these steps to determine your situation
   and fix it:
    1. Hold down the Option key and choose System Information from the
       Apple menu.
    2. In System Information's sidebar, under Software, select
       Installations.
    3. If the listings aren't arranged in alphabetical order, click
       Software Name to sort them.
    4. Look for Incompatible Kernel Extension Configuration Data. If the
       most recent version installed is 3.28.1, you have the troublesome
       version, and will need to force an update to 3.28.2. If you already
       have 3.28.2, as in the screenshot below, the kernel extension isn't
       the culprit and you'll have to try another troubleshooting method.
       [2][tn_System-Information-Incompatible-Kernel.jpg]

   If you need to force an update to 3.28.2 and have a Wi-Fi connection,
   the fix is easy: Open Terminal in /Applications/Utilities, type the
   following command, and press Return:

   sudo softwareupdate --background

   You may be prompted to enter your administrator password. After that,
   quit Terminal and restart your Mac to finish applying the fix.

   If you can't connect to Wi-Fi or don't have a Wi-Fi network, then you
   unfortunately have a more involved process ahead of you, detailed in
   the aforementioned Apple support article.

   We're happy that Apple addressed this issue quickly, but we can't say
   that the broken 3.28.1 update gives us warm and fuzzy feelings for the
   state of Apple's software quality assurance.

References

   1. https://support.apple.com/en-us/HT6672
   2. http://tidbits.com/resources/2016-02/System-Information-Incompatible-Kernel.png

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