I've rebooted my Debian and realize my ethernet card is not working. Cable seems unplugged. My hardware is:
05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
Tried installing r8168 driver from Realtek website and ethernet became crazy with these messages:
Feb 15 22:34:04 debian kernel: [ 9.264536] userif-3: sent link down event.
Feb 15 22:34:05 debian kernel: [ 9.264538] userif-3: sent link up event.
Feb 15 22:34:05 debian kernel: [ 10.265169] userif-3: sent link down event.
Tried DKMS after turning back to r8169 driver, which seems a cool thing to have. But this didn't solve my problem too. Here was my fix, which found by random tryouts (please understand a hopeless geek while eth0 is not working):
Yes. It was vmware-player's shitty network bug, which affected my ethernet driver (guess somehow via bridge interface?).