Reference Guide

Example: When the dcb-input or dcb-output policy is configured on interfaces or stack ports with the
dcb-buffer threshold policy, the following error message is displayed:
%Error: Deprecated command is not supported on interfaces with dcb-buffer-
threshold configured
You must not modify the service-class dot1p mappings when any buffer-threshold-policy is configured
on the system.
S4810-1(conf)#service-class dot1p-mapping dot1p0 3
% Error: PFC buffer-threshold policies conflict with dot1p mappings. Please
remove all dcb-buffer-threshold policies to change mappings.
The show dcb command has been enhanced to display the following additional buffer-related
information:
S4810-YU-MR-Dell (conf)#do show dcb
dcb Status : Enabled
PFC Queue Count : 2 --Indicate the PFC queue configured.
Total buffer (lossy + lossless)(in KB): 7787--Total buffer space for lossy and
lossless queues
PFC total buffer (in KB): 6526 --Indicates the total buffer (configured or
default)
PFC shared buffer (in KB): 832--Indicates the shared buffer (Configured or
default)
PFC available buffer ( in KB): 5694--Indicates remaining available buffers for
PFC that are free to be allocated
Configuring the Dynamic Buffer Method
Priority-based flow control using dynamic buffer spaces is supported on the S4820T platform.
To configure the dynamic buffer capability, perform the following steps:
1. Enable the DCB application. By default, DCB is enabled and link-level flow control is disabled on all
interfaces.
CONFIGURATION mode
S6000-109-Dell(conf)#dcb enable
2. Configure the shared PFC buffer size and the total buffer size. A maximum of 4 lossless queues are
supported.
CONFIGURATION mode
S6000-109-Dell(conf)#dcb pfc-shared-buffer-size 4000
S6000-109-Dell(conf)#dcb pfc-total-buffer-size 5000
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Data Center Bridging (DCB)