A vNetwork Distributed Switch (vDS) functions as a single virtual switch across all associated hosts. This enables you to set network configurations that span across all member hosts, and allows virtual machines to maintain consistent network configuration as they migrate across multiple hosts.

vNetwork Distributed Switch Network
A vNetwork Distributed Switch network

Like a vNetwork Standard Switch, each vNetwork Distributed Switch is a network hub that virtual machines can use. A vNetwork Distributed Switch can forward traffic internally between virtual machines or link to an external network by connecting to physical Ethernet adapters, also known as uplink adapters.

Each vNetwork Distributed Switch can also have one or more dvPort groups assigned to it. dvPort groups group multiple ports under a common configuration and provide a stable anchor point for virtual machines connecting to labeled networks. Each dvPort group is identified by a network label, which is unique to the current datacenter. A VLAN ID, which restricts port group traffic to a logical Ethernet segment within the physical network, is optional.

Network resource pools allow you to manage network traffic by type of network traffic.

In addition to VMware vNetwork Distributed Switches, vSphere 4 also provides support for third-party virtual switches. For information about configuring these third-party switches, go to http://www.cisco.com/go/1000vdocs.