How to enable promiscuous Mode on VMware
Note: Setting the vSwitch to promiscuous mode to support multiple devices per port using the standard vSwtich has significant negative effects on system performance and should be avoided if possible.
If a Nexus 1000v vSwitch is used in conjunction with vSphere, neither setting the vSwitch to promiscuous mode or using the “Use Source MAC address from Physical Interface” feature in the STC GUI is required. Multiple devices with random MAC Addresses is supported in this configuration without performance impacts. The Nexus 1000v vSwitch is a learning switch, and behaves like any standard hardware based switch.