Asus P9D-MH/SAS/10G-DUAL - Manual (Page 45)

ASUS P9D-MH Series 2-25
7. PCIE LINK Status LED (PCIE_LINKUP1)
This LED is for the PCIE link status of the Broadcom 10GbE chip. The unlit LED
indicates the PCIE link status is not established and green LED indicates activity or
operational condition.
8. Data Layer LED (DL_ACTIVE1)
This LED is for the data layer link status of the Broadcom 10GbE chip. If unlit, the
Broadcom 10GbE chip is either in fault state or a problem have occured.