Overview
A quick guide to bringing physical network interfaces (vmnics) up or down on an ESXi 5.0 host using the esxcli command via Tech Support Mode.

Change the link state from the Management Network vmkernel:
Log in to the ESXi 5.0 host using Tech Support Mode with root account privilege. Change the link state of the uplink vmnic with one of these commands:
esxcli network nic down -n vmnicX esxcli network nic up -n vmnicX
Where X is the vmnic number (for example vmnic0, vmnic1 …)
All Done.
