Nikon D6 Reference Manual page 989

Wired LAN/WT
G button U B setup menu
Adjust settings for upload to a computer or ftp server
connected via an Ethernet cable or optional WT-6 wireless
transmitter.
Wired LAN/WT Functions
Select [Enable] to enable connection via Ethernet or a wireless
transmitter. The camera's built-in Bluetooth and Wi-Fi turn off.
Choose Hardware
Choose the connection type: Ethernet ("wired LAN") or wireless
LAN.
B The Setup Menu: Camera Setup 937