Dell S4810 Reference Manual page 564

Step Task
bandwidth, the unused bandwidth is made
available to other priority groups.
Example: priority-group 0 bandwidth 60 pfc
off priority-group 1 bandwidth 20 pfc on
priority-group 2 bandwidth 20 pfc on
priority-group 4 strict-priority pfc off
Repeat this step to configure PFC and ETS
traffic handling for each priority group.
Specify the dot1p priority-to-priority group
3
mapping for each priority. Priority-group
range: 0 to 7. All priorities that map to the
same queue must be in the same priority
group.
Leave a space between each priority group
number. For example: priority-pgid 0 0 0 1 2
4 4 4 in which priority group 0 maps to dot1p
priorities 0, 1, and 2; priority group 1 maps to
dot1p priority 3; priority group 2 maps to
dot1p priority 4; priority group 4 maps to
dot1p priorities 5, 6, and 7.
Important Points to Remember
• If you remove a dot1p priority-to-priority group mapping from a DCB map (no priority pgid
command), the PFC and ETS parameters revert to their default values on the interfaces on which the
DCB map is applied. By default, PFC is not applied on specific 802.1p priorities; ETS assigns equal
bandwidth to each 802.1p priority.
As a result, PFC and lossless port queues are disabled on 802.1p priorities, and all priorities are
mapped to the same priority queue and equally share the port bandwidth.
• To change the ETS bandwidth allocation configured for a priority group in a DCB map, do not modify
the existing DCB map configuration. Instead, first create a new DCB map with the desired PFC and
ETS settings, and apply the new map to the interfaces to override the previous DCB map settings.
Then, delete the original dot1p priority-priority group mapping.
If you delete the dot1p priority-priority group mapping (no priority pgid command) before you
apply the new DCB map, the default PFC and ETS parameters are applied on the interfaces. This
change may create a DCB mismatch with peer DCB devices and interrupt network operation.
Applying a DCB Map on a Port
When you apply a DCB map with PFC enabled on an S6000 interface, a memory buffer for PFC-enabled
priority traffic is automatically allocated. The buffer size is allocated according to the number of PFC-
enabled priorities in the assigned map.
To apply a DCB map to an Ethernet port, follow these steps:
564
Command
priority-pgid
dot1p0_group_num
dot1p1_group_num
dot1p2_group_num
dot1p3_group_num
dot1p4_group_num
dot1p5_group_num
dot1p6_group_num
dot1p7_group_num
Command Mode
DCB MAP
Data Center Bridging (DCB)