Technical data

Fabric OS Administrator’s Guide 13-7
Publication Number: 53-0000518-09
Zoning Concepts
13
• Is exclusively enforced through selective information presented to end nodes through the fabric
Simple Name Server (SNS). When an initiator queries the name server for accessible devices in the
fabric, the name server returns only those devices that are in the same zone as the initiator. Devices
that are not part of the zone are not returned as accessible devices.
Hardware-Enforced Zoning
Hardware-enforced zoning is specified without using the mixed zoning scheme (mixed zones contain
domains, ports and WWNs as zone members). Brocade switches augment software-enforced zoning
with hardware enforcement. The exact methodology varies on different switch models.
Hardware-enforced zoning (also called hard zoning):
• Prevents a host from accessing a device it is not authorized to access.
• Checks each frame before it is delivered to a zone member and discards it if there is a zone
mismatch. When hardware-enforced zoning is active, the Brocade switch monitors the
communications and blocks any frames that do not comply with the effective zone configuration.
The switch performs this blocking at the transmit side of the port on which the destination device is
located.
• Is enforced at the ASIC level. Each ASIC maintains a list of source port IDs that have permission to
access any of the ports on that ASIC.
Fabric OS uses hardware-enforced zoning (on a per-zone basis) whenever the fabric membership or
zone configuration changes.