Administrator Guide

Table 18. Configuring Lossless Queues (continued)
Step Task Command Command Mode
on which a DCB map with
PFC enabled has been
applied, or which is already
configured for PFC using the
pfc priority command.
Range: 0-3. Separate queue
values with a comma; specify
a priority range with a dash;
for example: pfc no-drop
queues 1,3 or pfc no-drop
queues 2-3 Default: No
lossless queues are
configured.
Applying a DCB Map on a Line Card
On the C9010, DCB is supported per-line card. If the traffic handled by a DCB map is transmitted on ports on different line
cards, you must manually configure the DCB map on the backplane ports of the C9010 line cards on which the ports reside.
● Apply a DCB map with PFC and ETS settings on the backplane ports of C9010 line cards.
CONFIGURATION mode
dcb-map {linecard {0-11 | all} [port-set {0-3 | all}] backplane all dcb-map-name
NOTE:
On the C9010, linecard 10 and linecard 11 correspond to RPM0 and RPM1 respectively. To enable DCB
across C9010 line cards, apply a DCB map on all installed line cards (linecard 0–9) and RPMs (linecard 10–11).
NOTE: If the DCB map you apply to the backplane ports of C9010 RPMs (linecard 10–11) configures two or more
priority groups, you must increase the size of the PFC shared and total buffers (dcb pfc-shared-buffer-size
and dcb pfc-total-buffer-size commands).
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.
● The PFC memory buffer supports up to 2 lossless queues per port on all PFC enabled ports.
● PFC and ETS are globally enabled by default.
The default dot1p priority-queue assignments are applied as follows:
Dell(conf)#do show qos dot1p-queue-mapping
Dot1p Priority : 0 1 2 3 4 5 6 7
Queue : 1 0 2 3 4 5 6 7
Dell(conf)#
Dell(conf)#dcb enable pfc-queues ?
<1-4> Number of PFC lossless queues(default=2)
<1-4> Number of PFC lossless queues(default=2)
NOTE: In Egress queue assignment (8 queues).
PFC is not applied on specific dot1p priorities.
ETS: Equal bandwidth is assigned to each port queue and each dot1p priority in a priority group.
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Data Center Bridging (DCB)