Brocade Fabric OS Administrators Guide (Supporting Fabric OS v7.3.0) - Manual (Page 385)

FIGURE 52 Traffic prioritization in a logical fabric
High-availability considerations for QoS zone-based traffic
prioritization
If the standby control processor (CP) is running a Fabric OS version earlier than 6.3.0 and is
synchronized with the active CP, then QoS zones using D,I notation cannot be created. If the standby
CP is not synchronized or if no standby CP exists, then the QoS zone creation succeeds.
If QoS zones using D,I notation exist in either the defined or active configuration and the standby CP
tries to synchronize with the active CP, the synchronization fails if the standby CP is running a Fabric
OS version earlier than 6.3.0. Synchronization can succeed only if the QoS D,I zones are removed.
Supported configurations for QoS zone-based traffic prioritization
The following configuration rules apply to QoS zone-based traffic prioritization:
• All switches in the fabric must be running Fabric OS v6.0.0 or later.
ATTENTION
If QoS traffic crosses an ISL for a switch running a firmware version earlier than Fabric OS v6.0.0, the
frames are dropped.
• By default, all devices are assigned medium priority.
‐ To be assigned high or low priority, hosts and targets must be connected to a Brocade 8-
Gbps or 16-Gbps switch or port blade.
‐ To preserve the priority level across ISLs, the switches must be running Fabric OS v6.0.0 or
later.
• QoS is enabled by default on 8-Gbps and higher ports. QoS is disabled by default on all 4-Gbps
ports and long-distance ports.
High-availability considerations for QoS zone-based traffic prioritization
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