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NOTE: Dell EMC Networking does not recommend mapping all ingress traffic to a single queue when using PFC and ETS.
However, Dell EMC Networking does recommend using Ingress traffic classification using the service-class dynamic
dot1p command (honor dot1p) on all DCB-enabled interfaces. If you use L2 class maps to map dot1p priority traffic to
egress queues, take into account the default dot1p-queue assignments in the following table and the maximum number of
two lossless queues supported on a port (refer to Configuring Lossless Queues).
Although Dell EMC Networking OS allows you to change the default dot1p priority-queue assignments (refer to Setting
dot1p Priorities for Incoming Traffic), DCB policies applied to an interface may become invalid if you reconfigure dot1p-
queue mapping. If the configured DCB policy remains valid, the change in the dot1p-queue assignment is allowed.
NOTE: Although, each port on the S4810, S4820T, and S5000 devices support 8 QoS queues, you can configure only 4
QoS queues (0-3) to manage data traffic. The remaining 4 queues (4-7) are reserved for control traffic.
dot1p Value in
the Incoming
Frame
Egress Queue Assignment
0 0
1 0
2 0
3 1
4 2
5 3
6 3
7 3
dot1p Value in
the Incoming
Frame
Egress Queue Assignment
0 2
1 0
2 1
3 3
4 4
5 5
6 6
7 7
Data Center Bridging: Default Configuration
Before you configure PFC and ETS on a switch see the priority group setting taken into account the following default settings:
DCB is enabled.
PFC and ETS are globally enabled by default.
The default dot1p priority-queue assignments are applied as follows:
DellEMC(conf)#do show qos dot1p-queue-mapping
Dot1p Priority : 0 1 2 3 4 5 6 7
Queue : 0 0 0 1 2 3 3 3
DellEMC(conf)#
PFC is not applied on specific dot1p priorities.
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Data Center Bridging (DCB)