Configuring DCB Maps and its Attributes
This topic contains the following sections that describe how to configure a DCB map, apply the
configured DCB map to a port, configure PFC without a DCB map, and configure lossless queues.

DCB Map: Configuration Procedure

A DCB map consists of PFC and ETS parameters. By default, PFC is not enabled on any 802.1p priority
and ETS allocates equal bandwidth to each priority. To configure user-defined PFC and ETS settings, you
must create a DCB map.
Step Task Command Command Mode
1Enter global configuration mode to create a
DCB map or edit PFC and ETS settings. dcb-map name CONFIGURATION
2Configure the PFC setting (on or off) and the
ETS bandwidth percentage allocated to traffic
in each priority group, or whether the priority
group traffic should be handled with strict
priority scheduling. You can enable PFC on a
maximum of two priority queues on an
interface. Enabling PFC for dot1p priorities
makes the corresponding port queue lossless.
The sum of all allocated bandwidth
percentages in all groups in the DCB map
must be 100%. Strict-priority traffic is serviced
first. Afterwards, 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.
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.
priority-group
group_num {bandwidth
percentage | strict-
priority} pfc {on | off}
DCB MAP
3Specify the dot1p priority-to-priority group
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.
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
256 Data Center Bridging (DCB)