Developers Guide

Usage
Information
● When you configure lossless queues on an interface, PFC priority configuration is not allowed on the
dcb-map profile applied on the interface.
● The maximum number of lossless queues globally supported on the switch is two.
The following lists the dot1p priority-queue assignments.
dot1p Value in
the Incoming
Frame
Description heading
0 1
1 0
2 2
3 3
4 4
5 5
6 6
7 7
● Before configuring the port queues to function as no-drop queues, you must first apply the dcb-map
map with pfc mode off. To apply the dcb-map with pfc mode off, use the following commands:
dcb-map pfcoff and no pfc mode on.
pfc priority
Configure the CoS traffic to be stopped for the specified delay.
Syntax
pfc priority priority-range
To delete the pfc priority configuration, use the no pfc priority command.
Parameters
priority-range Enter the 802.1p values of the frames to be paused. Separate the priority values
with a comma; specify a priority range with a dash; for example, pfc priority 1,3,5-7.
The range is from 0 to 7.
Defaults none
Command Modes INTERFACE
Command
History
This guide is platform-specific. For command information about other platforms, refer to the relevant Dell
EMC Networking OS Command Line Reference Guide.
The following is a list of the Dell EMC Networking OS version history for this command.
Version Description
9.10(0.0) Introduced on the S6100-ON.
9.8(1.0) Introduced on the Z9100–ON.
9.7(0.0) Introduced on the Z9500.
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
The default number of 802.1p priorities that you can enable for PFC is 2. The maximum number of 802.1p
priorities that you can enable for PFC is –4. Queues to which PFC priority traffic is mapped are lossless
by default. Traffic may be interrupted due to an interface flap (going down and coming up) when you
reconfigure the lossless queues for no-drop priorities.
470 Data Center Bridging (DCB)