Administrator Guide

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 the 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, rst 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. The maximum number of
priority groups is 3.
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.
• On the C9010, DCB is supported per-line card. If the trac handled by a DCB map is transmitted on ports on dierent line cards, you
must manually congure the DCB map on the backplane ports of the C9010 line cards on which the ports reside (dcb-map
linecard all backplane all command).
If the DCB map you apply to the backplane ports of C9010 RPMs (linecard 10–11) congures two or more priority groups, you
must increase the size of the PFC shared and total buers (
dcb pfc-shared-buffer-size and dcb pfc-total-buffer-
size commands).
Applying a DCB Map on a Port
When you apply a DCB map with PFC enabled on a switch interface, a memory buer for PFC-enabled priority trac is automatically
allocated. The buer 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:
Table 16. Applying a DCB map to an Ethernet port
Step Task Command Command Mode
1
Enter interface conguration
mode on an Ethernet port.
interface
{tengigabitEthernet slot/
port fortygigabitEthernet
slot/port}
CONFIGURATION
2
Apply the DCB map on the
Ethernet port to congure it
with the PFC and ETS settings
in the map; for example:
Dell# interface
tengigabitEthernet 1/1
Dell(cong-if-te-1/1)# dcb-map
SAN_A_dcb_map1 Repeat
Steps 1 and 2 to apply a DCB
map to more than one port.
dcb-map name
INTERFACE
270 Data Center Bridging (DCB)