[MakeTechEasier: How to Fix a Mac with WiFi Problems and Dropping Connection](
  https://www.maketecheasier.com/fix-mac-wifi-problems/)
[MacWorld: How to fix Wi-Fi not working problems on Mac](
  https://www.macworld.co.uk/how-to/mac/how-fix-wifi-not-working-problems-on-mac-3605043/)
  
Source: https://gitlab.fokus.fraunhofer.de/snippets/59

1. Check:
    - Connected (on [layer 2](
      https://en.wikipedia.org/wiki/OSI_model#Layer_2:_Data_Link_Layer))?
    - Got IPaddress via DHCP?
    - can ping `fokus.fraunhofer.de` or 9.9.9.9?
      (Do **NOT** set non-fokus DNS servers!)
2. Check for updates of macOS
3. Disable Bluetooth
4. Lower MTU (commonly 1453 is recommended...)
5. Try 5GHz - **TODO**
   [Force 5GHz](
   https://apple.stackexchange.com/questions/131852/how-do-you-force-a-5-ghz-wifi-connection/202085)
6. Change "location"? (Network Settings -> Edit locations, create a new one)
7. Use Apple's Wireless Diagnostics:
   Either search for it using Spotlight (Cmd + spacebar), or hold Option/Alt 
   and click on the Wi-Fi icon at the top right of the screen, then select 
   Open Wireless Diagnostics.
   Before you click Continue to run a report, go to the menu and click on 
   Window > Performance/Fenster > Leistung (or hit Alt + Cmd + 5)
8. [Reset your SMC, PRAM or NVRAM](
   https://www.macworld.com/article/2881177/macs/how-to-reset-your-macs-nvram-pram-and-smc.html)
   - __PRAM/NVRAM__  
    Press and hold the power button on your Mac to completely shut it off. 
    Hard discs and fans need to stop spinning, and the screen needs to go dark.
    Power on your Mac.
    Immediately after you hear the startup sound, press and hold the 
    “Command + Option + P + R” keys.
    Keep holding them down until you hear the start up sound again and see the 
    Apple logo.
    Release the keys, and the PRAM/NVRAM will have been reset.
  - __SMC__
    - **Desktop Macs:** Disconnect the power cord (either from the Mac or 
      from the AC outlet). Wait 15 seconds and plug it back in. Then wait 
      another 5 seconds and turn the Mac back on.
    - **Portable Macs with non-removable batteries:** Shut down and unplug 
      your Mac. On the built-in keyboard, press and hold the Shift, Option, 
      and Control keys on the left side and press the power button and hold 
      all of these down for 10 seconds, then release the keys. Connect the 
      power adapter and then turn the Mac on normally.
    - **Portable Macs with removable batteries:** Shut down your Mac. 
      Disconnect the power cord and remove the battery. Press the power 
      button, hold it for 5 seconds, and then let go. Put the battery 
      back in, reconnect the power cord, and turn the Mac on normally.

# EoF