Hewlett Packard Enterprise FlexFabric 5940 Series, Руководство по настройке

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CND
A CND is a set of RPs and CPs enabled with QCN for a CNPV. CNDs are identified based on CNPVs.
Devices enabled with QCN for a CNPV are assigned to the corresponding CND. A CNPV-based
CND prevents traffic from outside the CND from entering the CND. If a frame from outside the CND
includes the CNPV, the 802.1p priority value of the frame is mapped to a configured alternate priority
value.
CND defense mode
Each interface on a device in a CND has a defense mode, which is statically configured or negotiated
through LLDP.
The following defense modes are available:
•
disabled
—Disables congestion notification and performs priority mapping according to the
priority mapping table.
•
edge
—Maps the priority of incoming frames with a CNPV to an alternate priority and removes
CN tags before sending out the frames.
•
interior
—Does not alter the priority of incoming frames with a CNPV and removes CN tags
before sending out the frames.
•
interiorReady
—Does not alter the priority of incoming frames with a CNPV and retains CN
tags when sending out the frames.
Priority mapping
Incoming frames with a CNPV are assigned to the corresponding output queue enabled with QCN.
Traffic with other priority values cannot enter that output queue. Priority-to-queue mappings are
determined by the QoS priority mapping table (see "
Configuring priority mapping ").
Modifying the priority mapping table for traffic with specific CNPVs might cause the system to fail to
detect congestion.
When you map multiple 802.1p priorities to one queue, all packets with these 802.1p priorities will be
included when determining congestion conditions. Therefore, do not map 802.1p priorities not
enabled with QCN to a queue enabled with QCN.
The marking action configured in a QoS policy affects priority mapping. For more information about
marking actions, see "
Configuring priority marking ."
The priority trust mode must be configured as the 802.1p priority. For information about configuring
trust modes, see "
Configuring priority mapping ."
The default port priority cannot be the same as the CNPV. For information about port priority, see
"
Configuring priority mapping ."
Protocols and standards
IEEE 802.1Qau, Congestion notification
QCN configuration task list
Tasks at a glance
(Required.) Enabling QCN