Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 513)

‐ Logical chassis cluster mode without any extra configuration
‐ Fabric cluster mode with the proper Converged Enhanced Ethernet (CEE) map
configuration
• Auto QoS only supports IPv4 addressing.
• Auto QoS can only be activated when the CEE map is set to the default values.
• If long distance ISL is configured, you cannot enable Auto QoS.
• Different NAS traffic types are not distinguished, and all NAS traffic types are treated equally. This
means all NAS traffic, whatever the type, share a common bandwidth guarantee. Individual traffic
types do not get separate bandwidth guarantees.
• In order to provide a minimum bandwidth guarantee for NAS traffic across switches in the fabric,
when Auto QoS is enabled for NAS, the CEE map reserves 20% of the available bandwidth for NAS
traffic.
• Port-level configuration has higher precedence than the NAS configuration. This means that any
interface-specific configuration will override the global configuration.
• The conform and exceed traffic class values are not set for the NAS traffic class when Auto QoS for
NAS is enabled.
• If all QoS Ternary Content-Addressable Memory (TCAM) space is used up already, enabling Auto
QoS will not have any impact on NAS traffic.
• The ACL byte counter is not supported on Brocade VDX 6740 series platforms.
• You cannot change the traffic class for NAS-classified traffic; it is always assigned to traffic-class
TC5.
• PFC is always turned OFF for the NAS classified traffic and cannot be made lossless.
• Auto QoS traffic classification is always done in the ingress RBridge. Once the traffic is classified, all
other nodes in the cluster automatically provision the minimum bandwidth guarantee of 20% through
their CEE map.
• The bandwidth available for Auto QoS traffic (20%) is fixed and cannot be modified. The following
error is shown if you attempt to change the value.
switch(config-cee-map-default)# priority-group-table 2 weight 30 pfc off
switch(config-cee-map-default)# priority-group-table 3 weight 30 pfc off
%Error: PGID 3 cannot be modified when 'nas auto-qos' is configured
• Automatic Migration of Port Profiles (AMPP) and Auto-NAS cannot be active on the same switch.
This means that if the CEE map is part of AMPP port profile, Auto QoS cannot be enabled, and if
Auto QoS is enabled and the CEE map is then associated to AMPP port profile, Auto QoS cannot be
disabled. In order to disable Auto QoS, you must:
1. Disassociate the CEE map from the port profile.
2. Disable Auto QoS.
3. Associate the CEE map with the AMPP port profile.
Auto QoS and CEE maps
In order to provide minimum bandwidth guarantee for NAS traffic across switches in the fabric, the
default CEE map has to be changed to accommodate NAS traffic. By default, the bandwidth division in
the CEE map is 40% for FCoE traffic and 60% for LAN traffic. As NAS traffic has to co-exist with FCoE
traffic, some of the LAN traffic bandwidth allocation is given over to NAS traffic. When Auto QoS is
enabled, the bandwidth allocations are 40% for FCoE traffic, 20% for NAS traffic and 40% for LAN
traffic. The purpose of using a CEE map is to pass along the scheduler weights to ISLs in the fabric so
that they will treat the NAS traffic accordingly.
Auto QoS and CEE maps
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