HP Virtual Connect: Common Myths, Misperceptions, and Objections, Second Edition

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are assigned to one of the vSwitches and the vSwitches are then associated with real physical NICs
residing in I/O slots on the hypervisor host. The vSwitches can have one or more physical NICs
(uplinks) assigned to them to provide external network connectivity. If more than one physical NIC is
assigned to the same vSwitch, network redundancy and/or load balancing is provided for the internal
servers (VMs) assigned to that vSwitch. The physical NICs then present one or more MAC addresses
to the external network, depending on the number of VMs communicating to the external network
through each physical NIC.
A Comparative Description of the VC Components
Referencing Figure 1 below, the c-Class enclosure (right) is a single physical enclosure that hosts one
or more real physical servers, called a server blade. In addition, the c-Class enclosure provides
external network connectivity to the internal servers (server blades) using a hardware implementation
of a layer 2 bridge, called a Virtual Connect Ethernet network (vNet). The server blade’s physical
NICs (pNics) are assigned to one of the vNets and the vNets are then associated with real physical
VC uplink ports from VC-Enet modules residing in the I/O bays on the c-Class enclosure. The vNets
can have one or more VC uplinks assigned to them to provide external network connectivity. If more
than one VC uplink is assigned to the same vNet, network redundancy and/or load balancing is
provided for the internal servers (server blades) assigned to that vNet. The VC uplinks then present
one or more MAC addresses to the external network, depending on the number of server blades
communicating to the external network through each VC uplink.
Figure 1: Hypervisor Networking Technology compared to Virtual Connect
After comparing the components and their functionality, it is obvious why many customers treat a c-
Class enclosure with Virtual Connect the same way they would a single host running a hypervisor. In
other words, VC allows an entire c-Class blade enclosure to look to the network like one big
hypervisor host. From a network redundancy and load balancing perspective, from a security
perspective, and from a port monitoring perspective, VC simplifies the network connectivity for an