Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

CHAPTER
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37-1
Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
37
Configuring and Managing VSANs
You can achieve higher security and greater stability in Fibre Channel fabrics by using virtual SANs
(VSANs). VSANs provide isolation among devices that are physically connected to the same fabric.
With VSANs you can create multiple logical SANs over a common physical infrastructure. Each VSAN
can contain up to 239 switches and has an independent address space that allows identical Fibre Channel
IDs (FC IDs) to be used simultaneously in different VSANs. This chapter includes the following
sections:
• Information About VSANs, page 37-1
• Configuring VSANs, page 37-5
• Displaying Static VSAN Configuration, page 37-11
• Default Settings, page 37-11
Information About VSANs
A VSAN is a virtual storage area network (SAN). A SAN is a dedicated network that interconnects hosts
and storage devices primarily to exchange SCSI traffic. In SANs you use the physical links to make these
interconnections. A set of protocols run over the SAN to handle routing, naming, and zoning. You can
design multiple SANs with different topologies.
This section describes VSANs and includes the following topics:
• VSAN Topologies, page 37-1
• VSAN Advantages, page 37-3
• VSANs Versus Zones, page 37-4
VSAN Topologies
With the introduction of VSANs, the network administrator can build a single topology containing
switches, links, and one or more VSANs. Each VSAN in this topology has the same operation and
property of a SAN. A VSAN has the following additional features:
• Multiple VSANs can share the same physical topology.
• The same Fibre Channel IDs (FC IDs) can be assigned to a host in another VSAN, which increases
VSAN scalability.
• Every instance of a VSAN runs all required protocols such as FSPF, domain manager, and zoning.