Windows 2011 SBS fresh install
Lenovo Server with 2 Intel network card
Was working fine for a month and then quit working. network cable is plugged in and lights are up but windows still show there is not cable plugged in. no communication between the server and the router.
What I try
try to plug the network cable to the other network card – did not work
replace the network cable
changing the speed and duplex
disable 1 network card
try a different router and switches
turn off all power management
going to do a driver update today – will update the results
You can also try uninstalling the NIC from Device Manager and then scan for hardware changes. If that doesn’t work then you probably have a bad NIC. If it’s under warranty Lenovo should replace it. Otherwise just get another NIC installed in the server and disable the onboard NICs.