The difference between a physical and virtual switch

Now that we understand the need for a virtual switch, it is essential to understand how different a virtual switch is when compared to a physical switch. The fact that VMware calls it a virtual switch is indicative of the fact that it can switch frames between its virtual ports or physical uplinks. So, is it any different from a physical switch? The answer is yes, in a couple of ways. One of the differences is the manner in which the virtual switch handles frame transfers:

When a frame enters a physical switch, its destination is determined by the switch port number corresponding to its destination MAC address in the physical switch's MAC table. If it can't find an entry in the MAC table, it floods the frame out via every port other than the source port. Much like the physical switch, a virtual switch also maintains a MAC table, but there is no learning process for a virtual switch. A virtual switch will already have a list of MAC addresses...