Brocade Fabric OS Administrator's Guide Supporting Fabric OS v6.3.0 (53-1001336-02, November 2009)

234 Fabric OS Administrator’s Guide
53-1001336-02
Broadcast zones
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The zone configuration is managed on a fabric basis. When a change in the configuration is saved,
enabled, or disabled according to the transactional model, it is automatically (by closing the
transaction) distributed to all switches in the fabric, preventing a single point of failure for zone
information.
NOTE
Zoning commands make changes that affect the entire fabric. When executing fabric-level
configuration tasks, allow time for the changes to propagate across the fabric before executing any
subsequent commands. For a large fabric, you should wait several minutes between commands.
Best practices for zoning
The following are recommendations for using zoning:
• Always zone using the highest Fabric OS-level switch.
Switches with earlier Fabric OS versions do not have the capability to view all the functionality
that a newer Fabric OS provides, as functionality is backwards compatible but not forwards
compatible.
• Zone using the core switch versus an edge switch.
• Zone using an enterprise-class platform rather than a switch.
An enterprise-class platform has more resources to handle zoning changes and
implementations.
Broadcast zones
Fibre Channel allows sending broadcast frames to all Nx_Ports if the frame is sent to a broadcast
well-known address (FFFFFF); however, many target devices and HBAs cannot handle broadcast
frames. To control which devices receive broadcast frames, you can create a special zone, called a
broadcast zone, which restricts broadcast packets to only those devices that are members of the
broadcast zone.
If there are no broadcast zones or if a broadcast zone is defined but not enabled, broadcast frames
are not forwarded to any F_Ports. If a broadcast zone is enabled, broadcast frames are delivered
only to those logged-in Nx_Ports that are members of the broadcast zone and are also in the same
zone (regular zone) as the sender of the broadcast packet.
Devices that are not members of the broadcast zone can send broadcast packets, even though
they cannot receive them.
A broadcast zone can have domain,port, WWN, and alias members.
Broadcast zones do not function in the same way as other zones. A broadcast zone does not allow
access within its members in any way. If you want to allow or restrict access between any devices,
you must create regular zones for that purpose. If two devices are not part of a regular zone, they
cannot exchange broadcast or unicast packets.
To restrict broadcast frames reaching broadcast-incapable devices, create a broadcast zone and
populate it with the devices that are capable of handling broadcast packets. Devices that cannot
handle broadcast frames must be kept out of the broadcast zone so that they do not receive any
broadcast frames.