I noticed that on our virtual environments (VMware ESX) based on  GNU/Linux (mostly Debian or Ubuntu distros ) the vmxnet modul is not used or not correctly loaded. Because of  lsmod shows also a loaded pcnet32 module which uses mii.

I added follwing script snippet to the /etc/init.d/open-vm-tools

 log_progress_msg "vmhgfs"; modprobe vmhgfs
 log_progress_msg "vmsync"; modprobe vmsync
 log_progress_msg "vmxnet - stoping network"; /etc/init.d/networking stop
 log_end_msg 0
 log_progress_msg "vmxnet - removing pcnet32"; rmmod pcnet32
 log_end_msg 0
 log_progress_msg "vmxnet - removing vmxnet"; rmmod vmxnet
 log_end_msg 0
 log_progress_msg "vmxnet - loading vmxnet "; modprobe vmxnet
 log_end_msg 0
 log_progress_msg "vmxnet - starting network";/etc/init.d/networking start
 log_end_msg 0

Check the dmesg out for:

[ 42.273810] vmxnet 0000:00:11.0: PCI INT A disabled
[ 51.808321] VMware vmxnet virtual NIC driver
[ 51.808422] vmxnet 0000:00:11.0: PCI INT A -> GSI 18 (level, low) -> IRQ 18
[ 51.815601] Found vmxnet/PCI at 0x1424, irq 18.
[ 51.816793] features: ipCsum zeroCopy partialHeaderCopy
[ 51.820787] numRxBuffers = 100, numRxBuffers2 = 1
[ 62.762575] eth0: no IPv6 routers present

This addon to the startup script removes the pcnet32 and vmxnet32 modules and loads explicit vmxnet. 🙂
Take care if you get an symbol not found error while loading the vmghfs module. If so you have to uncomment the loading of this module.

Have fun.