Asus RS724Q-E6/RS12 - Manual (Page 54)

4-8 Chapter 4: Motherboard information
4. LAN controller setting (3-pin LAN_SW1, LAN_SW2)
These jumpers allow you to enable or disable the onboard Intel ® Intel
82574LGigabit LAN controllers. Set to pins 1–2 to activate the Gigabit LAN
feature.