from jmicron :
‘According to your description, I think you may use our last generation Gigabit Ethernet controller – JMC251A, this chip was mass production at 2008Y, at that time, the IEEE802.3az specification was not ready yet. So the JMC251A chip might have a connection issue when it connects to other Gigabit Ethernet controller which supports IEEE802.3az and the ‘Speed & Duplex’ of JMC251A sets to ”Auto Negotiation” or ”1Gbps/Full Duplex”, then the link function will abnormal. Therefore our S/W engineer made a workaround – ASD(Auto-Speed-Down) function to force the LAN speed keeping in 100Mbps when user sets the ‘Speed & Duplex’ to “Auto Negotiation” or ”1Gbps/Full Duplex”. My suggestion is to use non-support IEEE802.3az Gigabit switch then your connection speed would keep as 1Gbps.’
Also Thread "Gelöst".
Vielen Dank!
Gruß Dreamrock