Cisco Nexus 5000 Series Switch Fabric Manager Software Configuration Guide, NX-OS 4.0 (OL-16598-01, June 2008)

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16-21
Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
Chapter 16 Configuring and Managing Zones
Zone Set Distribution
Zone Enforcement
Zoning can be enforced in two ways: soft and hard. Each end device (N port) discovers other devices in
the fabric by querying the name server. When a device logs in to the name server, the name server returns
the list of other devices that can be accessed by the querying device. If an N port does not know about
the FC IDs of other devices outside its zone, it cannot access those devices.
In soft zoning, zoning restrictions are applied only during interaction between the name server and the
end device. If an end device somehow knows the FC ID of a device outside its zone, it can access that
device.
Hard zoning is enforced by the hardware on each frame sent by an N port. As frames enter the switch,
source-destination IDs are compared with permitted combinations to allow the frame at wire speed. Hard
zoning is applied to all forms of zoning.
Note Hard zoning enforces zoning restrictions on every frame, and prevents unauthorized access.
Nexus 5000 Series switches support both hard and soft zoning.
Zone Set Distribution
You can distribute full zone sets using one of two methods: one-time distribution or full zone set
distribution. Table 16-1 lists the differences between the methods.
This section describes zone set distribution and includes the following topics:
• Enabling Full Zone Set Distribution, page 16-21
• Enabling a One-Time Distribution, page 16-22
• About Recovering from Link Isolation, page 16-23
• Importing and Exporting Zone Sets, page 16-23
Enabling Full Zone Set Distribution
All switches in the Nexus 5000 Series distribute active zone sets when new E port links come up or when
a new zone set is activated in a VSAN. The zone set distribution takes effect while sending merge
requests to the adjacent switch or while activating a zone set.
Table 16-1 Zone Set Distribution Differences
One-Time Distribution Full Zone Set Distribution
Distributes the full zone set immediately. Does not distribute the full zone set immediately.
Does not distribute the full zone set information
along with the active zone set during activation,
deactivation, or merge process.
Remembers to distribute the full zone set
information along with the active zone set during
activation, deactivation, and merge processes.