You can create abstracted network devices called vNetwork Standard Switches (vSwitches). A vSwitch can route traffic internally between virtual machines and link to external networks.

You can use vSwitches to combine the bandwidth of multiple network adapters and balance communications traffic among them. You can also configure a vSwitch to handle physical NIC failover.

A vSwitch models a physical Ethernet switch. The default number of logical ports for a vSwitch is 120. You can connect one network adapter of a virtual machine to each port. Each uplink adapter associated with a vSwitch uses one port. Each logical port on the vSwitch is a member of a single port group. Each vSwitch can also have one or more port groups assigned to it. For information about maximum allowed ports and port groups, see Configuration Maximums for vSphere 4.1.

When two or more virtual machines are connected to the same vSwitch, network traffic between them is routed locally. If an uplink adapter is attached to the vSwitch, each virtual machine can access the external network that the adapter is connected to.