Lenovo USB Dock 3.0

I have a Lenovo USB 3.0 Dock (not sure if 3.0 is a version number or just indicates USB 3).  It has an Ethernet connector, and to simplify taking the notebook with me, I was using that port instead of the built-in one on the notebook.  But it has never worked real well, so I have been plugging my Ethetnet cable into the notebook.  I have seen complaints by other Lenovo users about this.  The solution?  Disable the built-in Ethernet port under Network and Sharing Center->Change Adapter Settings, and enable the USB Ethernet port.  Then reboot.  It appears that having both enabled even with only one plugged in was causing IP address conflict problems.