Information Technology Reference
In-Depth Information
Virtualization is built from abstracting logical entities from pooled physical resources.
The Cisco network architectures for the enterprise data center contains many forms of
network and device virtualization technologies.
Key
To p i c
Figure 4-12 illustrates the many virtualization technologies in use today.
Virtual Machines
Virtual Switching Systems (VSS)
Virtual Switches
Virtual Private Networks (VPN)
Virtual Storage Area Networks (VSAN)
Virtual Routing and Forwarding (VRF)
Virtual Local Area Networks (VLAN)
Virtual Port Channels (vPC)
Virtual Device Contexts (VDC)
Figure 4-12
Data Center Virtualization Technologies
VSS
Virtual Switching System (VSS) is a network virtualization technology that allows two
physical Cisco Catalyst 6500 series switches to act as a single logical virtual switch. The
VSS increases operational efficiencies and scales bandwidth up to 1.4 Tb/s. This technol-
ogy is very similar to StackWise technology used with the Cisco Catalyst 3750 series
product line, which enables switches stacked together to operate as one and use a single
command-line interface (CLI) for management. However, VSS is limited to two physical
chassis connected together.
VRF
Virtual routing and forwarding (VRF) is a routing virtualization technology that creates
multiple logical Layer 3 routing and forwarding instances (route tables) that can function
on the same physical router. In Multiprotocol Label Switching (MPLS) VPN environments,
the use of VRF technology plays a major role by allowing multiple networks to coexist on
the same MPLS network. The routing information is contained inside the VRF and is visi-
ble only to routers participating in the same VRF. Because the routing information with
VRF is separated, duplicate IP addressing schemes can be used.
vPC
Virtual Port Channel (vPC) technology works by combining two Cisco Nexus 7000 series
switches or two Cisco Nexus 5000 series switches with 10GE links, which are then repre-
sented to other switches as a single logical switch for port channeling purposes. With
present in the physical topology.
