Setup Guide

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
DellEMC#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 EMC 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.
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.
Conguring PFC in a DCB Map
A switch supports the use of a DCB map in which you congure priority-based ow control (PFC) setting. To congure PFC parameters,
you must apply a DCB map on an interface.
PFC Conguration Notes
PFC provides ow control based on the 802.1p priorities in a converged Ethernet trac that is received on an interface and is enabled by
default when you enable DCB. As an enhancement to the existing Ethernet pause functionality, PFC stops trac transmission for specied
priorities (CoS values) without impacting other priority classes. Dierent trac types are assigned to dierent priority classes.
When trac congestion occurs, PFC sends a pause frame to a peer device with the CoS priority values of the trac that needs to be
stopped. DCBx provides the link-level exchange of PFC parameters between peer devices. PFC allows network administrators to create
zero-loss links for SAN trac that requires no-drop service, while at the same time retaining packet-drop congestion management for LAN
trac.
On a switch, PFC is enabled by default on Ethernet ports (pfc mode on command). You can congure PFC parameters using a DCB
map or the pfc priority command in Interface conguration mode. For more information, see Conguring Priority-Based Flow Control.
As soon as you apply a DCB map with PFC enabled on an interface, DCBx starts exchanging information with a peer. The IEEE802.1Qbb,
CEE and CIN versions of PFC TLV are supported. DCBx also validates PFC congurations that are received in TLVs from peer devices. By
applying a DCB map with PFC enabled, you enable PFC operations on ingress port trac. To achieve complete lossless handling of trac,
congure PFC priorities on all DCB egress ports.
286
Data Center Bridging (DCB)