When connecting a device with ADB Wireless,
got failed to authenticate to <ip>
adb devices gives the device shows up as unauthorized.
From Android 4.2, every ADB device needs to be authorized for a computer to connect. This is done for security. So when a USB is connected a prompt comes asking to authorize the device when USB debugging is set. But does not happen for WIFI ADB.
So the workaround is to connect the device by USB, accepting the machine always. Then when the Wireless ADB is tried, it should work.