Administrator Guide

Task Command Command Mode
Enable an MXL 10/40GbE Switch and M I/O Aggregator with
the FC Flex IO module for the Fibre Channel protocol.
feature fc
CONFIGURATION
Creating a DCB Map
Congure the priority-based ow control (PFC) and enhanced trac selection (ETS) settings in a DCB map before you apply them
on downstream server-facing ports on an MXL 10/40GbE Switch or an M I/O Aggregator with the FC Flex IO module.
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
Congure the PFC setting (on or o) and the ETS
bandwidth percentage allocated to trac in each priority
group. Congure whether the priority group trac should
be handled with strict-priority scheduling. The sum of all
allocated bandwidth percentages must be 100 percent.
Strict-priority trac is serviced rst. Afterward, bandwidth
allocated to other priority groups is made available and
allocated according to the specied 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 congure PFC and ETS trac 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 | o}
DCB MAP
3
Specify the priority group ID number to handle VLAN
trac 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
specic 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 congured for a priority group in a DCB map, do not modify the existing DCB map
conguration. 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.
932
FC Flex IO Modules