Link/Act Led - Realtek RTL8169 Manual

RTL8169

9.6.5 LINK/ACT LED

In 10/100/1000Mbps mode, blinking of the LINK/ACT LED indicates that the RTL8169 is linked and operating properly. This
LED high for extended periods, indicates that a link problem exists.
Power On
LED = High
No
Link?
Yes
LED = Low
No
Tx/Rx packet?
Yes
LED = High for (100 +- 10) ms
LED = Low for (12 +- 2) ms
2002/03/27 Rev.1.21
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