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What two statements are true about Fibre Channel zoning? (Choose two.)
A. Zones define paths to a Fibre Channel array
B. Zones control access to LUNs on a Fibre Channel storage array
C. Zones can be soft or hard
D. Zones can be configured on an array or ESXi host
Correct Answer: AC
Explanation/Reference:
Using Zoning with Fibre Channel SANs
Zoning provides access control in the SAN topology. Zoning defines which HBAs can connect to which targets. When you configure a SAN by using zoning, the devices outside a zone are not visible to the devices inside the zone.
Zoning has the following effects:
Reduces the number of targets and LUNs presented to a host.
Controls and isolates paths in a fabric.
Can prevent non-ESXi systems from accessing a particular storage system, and from possibly destroying VMFS data
Can be used to separate different environments, for example, a test from a production environment.
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.storage.doc_50%2FGUID-E7818A5D-6BD7-4F51-B4BA-EFBF2D3A8357.html
Soft and Hard zoning
The fabric name service allows each device to query the addresses of all other devices. Soft zoning restricts only the fabric name service, to show only an allowed subset of devices. Therefore, when a server looks at the content of the fabric, it will only see the devices it is allowed to see. However, any server can still attempt to contact any device on the network by address. In this way, soft zoning is similar to the computing concept of security through obscurity.
In contrast, hard zoning restricts actual communication across a fabric. This requires efficient hardware implementation (frame filtering) in the fabric switches, but is much more secure. As stated, modern switches will employ hard zoning when you implement soft.
http://en.wikipedia.org/wiki/Fibre_Channel_zoning#Soft_and_Hard_zoning
