Administrator Guide

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 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.
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
To apply a DCB map to an Ethernet port, follow these steps:
1 Enter interface conguration mode on an Ethernet port.
CONFIGURATION mode
interfacetengigabitEthernet slot/port
2 Apply the DCB map on the Ethernet port to congure it with the PFC and ETS settings in the map.
INTERFACE mode
dcb-map name
Dell# interface tengigabitEthernet 0/0
Dell(config-if-te-0/0)# dcb-map SAN_A_dcb_map1
Repeat Steps 1 and 2 to apply a DCB map to more than one port.You cannot apply a DCB map on an interface that has been already
congured for PFC using thepfc priority command or which is already congured for lossless queues (pfc no-drop
queues command).
Conguring PFC without a DCB Map
In a network topology that uses the default ETS bandwidth allocation (assigns equal bandwidth to each priority), you can also enable PFC
for specic dot1p-priorities on individual interfaces without using a DCB map. This type of DCB conguration is useful on interfaces that
require PFC for lossless trac, but do not transmit converged Ethernet trac.
1 Enter interface conguration mode on an Ethernet port.
CONFIGURATION mode
interface tengigabitEthernet slot/ port
2 Enable PFC on specied priorities. Range: 0-7. Default: None.Maximum number of lossless queues supported on an Ethernet port:
2.Separate priority values with a comma. Specify a priority range with a dash, for example: pfc priority 3,5-7.
946
FC Flex IO Modules