HP Brocade 8/24c HP Virtual Connect: Common Myths, Misperceptions, and Objecti - Page 5

Myths, Misconceptions and Objections #1: VC Ethernet is just another switch Incorrect: While VC uses tried-and-true, IEEE standard, Layer 2 bridging functionality, its primary purpose is to provide many server virtualization and management features that are non-existent in traditional switches. VC may perform some functions like a traditional switch; however, VC has many additional features which clearly distinguish it from a traditional switch. Likewise, server virtualization hypervisors (for example, VMware ESX, Microsoft Hyper-V, Citrix Xen) perform some functions of a traditional switch but, like VC, have many additional features which clearly distinguish them from a traditional switch. As a result, it is incorrect to say that either technology, VC or hypervisor virtual switching, is "just another switch". VC and server virtualization hypervisors are very similar in the networking functionality that they provide to servers; a hypervisor provides it for virtual servers and VC provides it for physical HP server blades. In the same way that a hypervisor provides this functionality in a way that interoperates with the external network, VC also provides this interoperable connectivity between HP server blades and the external network. Virtual Connect is not called a "switch" because it is not configured, deployed, or managed as a switch and does not present itself to the external network as a switch - again, much like a hypervisor. When Virtual Connect is linked to the external network, the external network "sees" the same behavior from VC as it "sees" when a server hosting a hypervisor is connected to the external network. Since VC is not configured, deployed, or managed like a traditional switch and presents itself to the network as an endpoint (like a server), it is incorrect to call VC a "switch". Important: Even though VC and server virtualization hypervisor networking technology similarities are being discussed, the two products provide a solution for completely different problems in the data center. As such, VC and server virtualization hypervisors (for example, VMware ESX, Microsoft Hyper-V, Citrix XEN, etc.) work together very well to provide a robust solution. Comparing VC and Server Virtualization Hypervisor Networking Technology One method of understanding how Virtual Connect operates on the LAN is to compare the Virtual Connect networking components and their functionality to the networking components of a server virtualization hypervisor (for example, VMware ESX, Microsoft Hyper-V, Citrix Xen). Since the networking technology behind hypervisors is commonly understood and accepted by many customers, understanding the many similarities between VC and hypervisors will help an implementer have a better understanding of how Virtual Connect looks to, and behaves on, the external network. Just to be clear, Virtual Connect and hypervisors are fundamentally different products and address completely different needs within the data center. This comparison is strictly about understanding the similarities between the two products in regards to networking technology in order to better understand Virtual Connect. A Description of the Hypervisor Components Referencing Figure 1 below, the hypervisor host (left) is a single physical server running a server virtualization hypervisor (for example, VMware ESX, Microsoft Hyper-V, Citrix Xen) that allows the physical server to host one or more instances of a virtual server, called a Virtual Machine (VM). In addition, the hypervisor host provides external network connectivity to the internal servers (VMs) using a virtual (software) implementation of a layer 2 bridge, called a vSwitch. The VM virtual NICs (vNics) 5