If you try to get into KACE K2000 box using the USB Ethernet dongle with the X1 Carbon (3rd Generation), you'll discover that it will get you to the menu and allow you to enter the password, but nothing else.

In order to get into the KACE K2000 box you have to use the replicator, OneLink or a Realtek RTL8153 Ethernet USB dongle.  You'll may have to create a KBE for the driver.