A vNetwork Distributed Switch functions as a single virtual switch across all associated hosts. This allows virtual machines to maintain a consistent network configuration as they migrate across multiple hosts.

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.

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