DNS error on laptop when tethered to non-rooted Android 5.1 device
Try enabling the developer options on your phone, and set the usb config to RNDIS manually (this should happen automatically when you set on usb tether, but [driver issues?]) If that does not do it, go for the USB debugging option, --not that either?
 OEM unlocking is next.. (these are all in the same developer menu)..

-I am not 100% if the OEM unlock is just to enable the bootloader, but when fixing this, I remembered a nasty little tid-bit how yankee phones' ability to tether is sometimes disabled, just to enable Service Providers to sell two internet-plans instead of one.. 
So, now all fired up, fighting for my rights, I just went all ham on all of the above, and now my tethering experience is smoother than ever.