The need for a software virtual switch

Most physical machines will have one or more network cards that will not only enable them to communicate with other networked components but also provide a unique network identity in terms of a MAC address and an IP address. Now, when you use a single machine to host several virtual machines running the same traditional operating systems that were once run on a physical machine, there surfaces a challenge that needs to be addressed. The challenge is: how do we assign unique identities for each of the virtual machines and how do we make them part of our organization's network? Part of the answer introduces the concept of a Virtual NIC (vNIC): which is created on a virtual machine to let it connect to the network. The second part of the challenge is the fact that although you have multiple vNICs connected to a virtual machine, there should be a way to channel the vNIC traffic out of an ESXi host via its physical NICs. This challenge is addressed...