Step Task Command Command Mode
1
Create a DCB map to specify PFC and ETS
settings for groups of dot1p priorities.
dcb-map name
CONFIGURATION
2
Configure the PFC setting (on or off) and the
ETS bandwidth percentage allocated to traffic
in each priority group. Configure whether the
priority group traffic should be handled with
strict-priority scheduling. The sum of all
allocated bandwidth percentages must be
100 percent. Strict-priority traffic is serviced
first. Afterward, bandwidth allocated to other
priority groups is made available and allocated
according to the specified percentages. If a
priority group does not use its allocated
bandwidth, the unused bandwidth is made
available to other priority groups.
Restriction: You can enable PFC on a
maximum of two priority queues.
Repeat this step to configure PFC and ETS
traffic handling for each priority group, for
example: priority-group 0 bandwidth
60 pfc off priority-group 1
bandwidth 20 pfc onpriority-group 2
bandwidth 20 pfc on
priority-group 4
strict-priority pfc off
priority-group
group_num {bandwidth
percentage | strict-
priority} pfc {on | off}
DCB MAP
3
Specify the priority group ID number to handle
VLAN traffic for each dot1p class-of-service: 0
through 7. Leave a space between each
priority group number. For example,
priority-pgid 0 0 0 1 2 4 4 4 where
dot1p priorities 0, 1, and 2 are mapped to
priority group 0; dot1p priority 3 is mapped to
priority group 1; dot1p priority 4 is mapped to
priority group 2; dot1p priorities 5, 6, and 7 are
mapped to priority group 4.
All priorities that map to the same egress
queue must be in the same priority group.
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
DCB MAP
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 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, 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-to-priority group mapping.
FC Flex IO Modules
1083
