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.
July 1, 2011