Users Guide

Lossless trac egresses out the no-drop queues. Ingress dot1p trac from PFC-enabled interfaces is automatically mapped to the no-drop
egress queues.
1 Enter INTERFACE Conguration mode.
CONFIGURATION mode
interface type slot/port/subport
2 Congure the port queues that will still function as no-drop queues for lossless trac.
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 two.
The range is from 0 to 7. Separate the queue values with a comma; specify a priority range with a dash; for example, pfc no-drop
queues 1,7 or pfc no-drop queues 2-7.
The default: No lossless queues are congured.
3 Congure to drop the unknown unicast packets ooding on lossless priorities.
CONFIGURATION mode
pfc-nodrop-priority l2-dlf drop
4 View the packets drop count corresponding to the priority.
EXEC mode
EXEC Privilege mode
show hardware pfc-nodrop-priority l2-dlf drops stack-unit stack-unit-number port-set port-
pipe
Dell#show hardware pfc-nodrop-priority l2-dlf drops stack-unit 0 port-set 0
---------------------------------------------------
Priority DropCount
---------------------------------------------------
0 0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
To clear the drop statistics, use the clear hardware pfc-nodrop-priority l2-dlf drops stack-unit stack-
unit-number
port-set port-pipe command.
NOTE
: Dell Networking OS Behavior: By default, no lossless queues are congured on a
port.
A limit of two lossless queues is supported on a port. If the amount of priority trac that you congure to be paused exceeds the two
lossless queues, an error message displays.
In S6000, any pfc-dot1p priorities congured on a given interface need not be the same across the system. In other words, lossless queue
limit is applicable on a per-port level and not on the global-cong context. For example, one of the Te/Fo interfaces can have pfc-dot1p
priorities as 2 and 3. Whereas, the other Te/Fo interface(s) can have its pfc-dot1p priorities as 4 and 5.
It is the user responsibility to have symmetric PFC congurations on the interfaces involved in a particular PFC-enabled trac-ow to
obtain lossless behavior.
Data Center Bridging (DCB)
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