Diagnostic LEDs v1.01 Link integrity ============== There are two sets of LEDs on the EtherExpress(TM) PRO/100 Smart adapter: - a yellow set for 10 Mbps operation, and - a green set for 100 Mbps operation. The LEDs are labeled LNK for link and ACT for activity. The 10 MB LNK LED indicates that a link pulse is present on the cable. The 100 MB LNK LED indicates that a link-idle pattern is present on the cable. The ACT LED indicates that there is read/write activity on the network. It doesn't always mean there is activity on the adapter. If you're using a crossover cable, load the drivers on both servers before trying to read the LEDs.