Reference Guide

Version Description
9.9(0.0) Introduced on the C9010.
9.6(0.0) Removed from the S-series. Replaced by the dcb-map
commands.
9.0.2.0 Introduced on the S6000.
8.3.19.0 Introduced on the S4820T.
8.3.12.0 Introduced on the S4810.
8.3.16.0 Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
If you apply an input policy with PFC disabled (no pfc mode on):
• You can enable link-level flow control on the interface. To delete the input
policy, first disable link-level flow control. PFC is then automatically enabled on
the interface because an interface is by default PFC-enabled.
• PFC still allows you to configure lossless queues on a port to ensure no-drop
handling of lossless traffic.
When you apply an input policy to an interface, an error message is displayed if:
• The PFC dot1p priorities result in more than two lossless port queues globally
on the switch.
• You already enabled link-level flow control. PFC and link-level flow control
cannot be enabled 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 map to a single priority group with a PGID
of 0 for DCBx negotiations.
Related
Commands
dcb-map— to configure PFC and ETS on Ethernet ports that support converged
Ethernet traffic.
Data Center Bridging (DCB)
641