interface type slot/port
2. Configure the port queues that still functions as no-drop queues for lossless traffic.
INTERFACE mode
pfc no-drop queues queue-range
For the dot1p-queue assignments, refer to the dot1p Priority-Queue Assignment table.
The maximum number of lossless queues globally supported on the switch is four.
The range is from 0 to 3. Separate the 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.
The default: No lossless queues are configured.
NOTE: Dell Networking OS Behavior: By default, no lossless queues are configured on a port.
A limit of two lossless queues is supported on a port. If the amount of priority traffic that you configure to
be paused exceeds the two lossless queues, an error message displays. Reconfigure the input policy
using a smaller number of PFC priorities.
If you configure lossless queues on an interface that already has a DCB input policy with PFC enabled
(pfc mode on), an error message displays.
Traffic may be interrupted due to an interface flap (going down and coming up) when you reconfigure
lossless queues on no-drop priorities in an input policy and re-apply the policy to an interface.
Configuring the PFC Buffer in a Switch Stack
In a switch stack, you must configure all stacked ports with the same PFC configuration. In addition, you
must configure a separate buffer of memory allocated exclusively to a service pool accessed by queues
on which priority-based control flows are mapped.
These PFC-enabled queues ensure the lossless transmission of storage and server traffic. The buffer
required for the PFC service pool is calculated based on the number of ports and port queues used by
PFC traffic.
You can configure the size of the PFC buffer for all switches in a stack or all port pipes on a specified
stack unit by entering the following commands on the master switch.
• Configure the PFC buffer for all switches in the stack.
CONFIGURATION mode
[no] dcb stack-unit all pfc-buffering pfc-port {1-56} pfc-queues {1-2}
By default, the PFC buffer is enabled on all ports on the stack unit.
• Configure the PFC buffer for all port pipes in a specified stack unit by specifying the port-pipe
number, number of PFC-enabled ports, and number of configured lossless queues.
CONFIGURATION mode
[no] dcb stack-unit stack-unit-id [port-set port-set-id] pfc-buffering pfc-
ports {1-56} pfc-queues {1-2}
Valid stack-unit IDs are 0 to 5.
Data Center Bridging (DCB) 263