Dell S4810 Reference Manual page 566

Configuring Lossless Queues
DCB also supports the manual configuration of lossless queues on an interface after you disable PFC
mode in a DCB map and apply the map on the interface. The configuration of no-drop queues provides
flexibility for ports on which PFC is not needed, but lossless traffic should egress from the interface.
Lossless traffic egresses out the no-drop queues. Ingress 802.1p traffic from PFC-enabled peers is
automatically mapped to the no-drop egress queues.
When configuring lossless queues on a port interface, consider the following points:
• By default, no lossless queues are configured on a port.
• A limit of two lossless queues are supported on a port. If the number of lossless queues configured
exceeds the maximum supported limit per port (two), an error message is displayed. You must re-
configure the value to a smaller number of queues.
• If you configure lossless queues on an interface that already has a DCB map with PFC enabled (pfc
on), an error message is displayed.
Step Task
1 Enter INTERFACE Configuration mode.
Open a DCB map and enter DCB map
2
configuration mode.
Disable PFC.
3
Return to interface configuration mode.
4
Apply the DCB map, created to disable the
5
PFC operation, on the interface
Configure the port queues that still function
6
as no-drop queues for lossless traffic. For
the dot1p-queue assignments.
The maximum number of lossless queues
globally supported on a port is 2.
You cannot configure PFC no-drop queues
on an interface on which a DCB map with
PFC enabled has been applied, or which is
already configured for PFC using the pfc
priority command.
Range: 0-3. Separate queue values with a
comma; specify a priority range with a dash;
for example: pfc no-drop queues 1,3 or pfc
no-drop queues 2-3 Default: No lossless
queues are configured.
566
Command
interface{tengigabitE
thernet slot/port |
fortygigabitEthernet
slot/port}
dcb-map name
no pfc mode on
exit
dcb-map {name |
default}
pfc no-drop
queuesqueue-range
Command Mode
CONFIGURATION
INTERFACE
DCB MAP
DCB MAP
INTERFACE
INTERFACE
Data Center Bridging (DCB)