Reference Guide

96 | Data Center Bridging
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• The PFC dot1p priorities result in more than two lossless port queues globally on the switch.
• You already enabled link-level flow control. You cannot enable PFC and link-level flow control at
the same time on an interface.
In a switch stack, configure all stacked ports with the same PFC configuration.
A DCB input policy for PFC applied to an interface may become invalid if you reconfigure the
dot1p-queue mapping. This situation occurs when the new dot1p-queue assignment exceeds the
maximum number (2) of lossless queues supported globally on the switch. In this case, all PFC
configurations received from PFC-enabled peers are removed and resynchronized with the peer
devices.
Traffic may be interrupted when you reconfigure PFC no-drop priorities in an input policy or reapply
the policy to an interface.
If the priority group to QoS policy mapping configurations in the DCB output profile are not complete
(for example, no priorities are mapped or only some of the priorities are mapped), all eight priorities
are mapped to a single priority group with a PGID of 0 for DCBx negotiations.
Related
Commands
dcb-policy input stack-unit stack-ports all
Apply the configuration source DCB parameters for both ETS and PFC parameters on all stack links.
Syntax
dcb-policy stack-unit {all|<0-5>}stack-ports all interface config-source-port
To remove all configuration source DCB parameters for ETS and PFC from all stack links, use the no
dcb-policy stack-unit {all|<0-5>} stack-ports all command.
Defaults
None
Command Modes
CONFIGURATION
Command
History
Usage
Information
This command is supported in Programmable-Mux (PMUX) mode only.
As soon as you apply a DCB policy with PFC enabled on an interface, DCBx starts exchanging
information with PFC-enabled peers. The IEEE802.1Qbb, CEE, and CIN versions of PFC TLV are
supported. DCBx also validates PFC configurations received in TLVs from peer devices.
By applying a DCB input policy with PFC enabled, you enable PFC operation on ingress port traffic.
To achieve complete lossless handling of traffic, also enable PFC on all DCB egress ports or configure
the dot1p priority-queue assignment of PFC priorities to lossless queues (refer to pfc no-drop
queues).
To remove a DCB input policy, including the PFC configuration it contains, enter the no
dcb-input
policy-name command in Interface configuration mode.
Related
Commands
dcb-input Creates a DCB input policy.
Version 9.2(0.0) Introduced on the M I/O Aggregator
dcb-policy input Applies the input policy with the PFC configuration.