Users Guide

Honor dot1p You can honor dot1p priorities in ingress traffic at the port or global switch level (refer
to Default dot1p to Queue Mapping) using the service-class dynamic dot1p
command in INTERFACE configuration mode.
Layer 2 class maps You can use dot1p priorities to classify traffic in a class map and apply a service policy
to an ingress port to map traffic to egress queues.
NOTE: Dell Networking does not recommend mapping all ingress traffic to a single queue when using
PFC and ETS. However, Dell Networking does recommend using Ingress traffic classification using the
service-class dynamic dot1p command (honor dot1p) on all DCB-enabled interfaces. If you use L2
class maps to map dot1p priority traffic to egress queues, take into account the default dot1p-queue
assignments in the following table and the maximum number of two lossless queues supported on a port
(refer to Configuring Lossless Queues).
Although Dell Networking OS allows you to change the default dot1p priority-queue assignments (refer to
Setting dot1p Priorities for Incoming Traffic), DCB policies applied to an interface may become invalid if
you reconfigure dot1p-queue mapping. If the configured DCB policy remains valid, the change in the
dot1p-queue assignment is allowed.
Configuring the Dynamic Buffer
Method
Priority-based flow control using dynamic buffer spaces is supported on the switch.
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
dcb enable
2 Configure the shared PFC buffer size and the total buffer size. A maximum of 4 lossless queues are
supported.
CONFIGURATION mode
dcb pfc-shared-buffer-size value
dcb pfc-total-buffer-size value
The buffer size range is from 0 to 3399. Default is 3088.
3 Configure the number of PFC queues.
CONFIGURATION mode
dcb enable pfc-queues pfc-queues
The number of ports supported based on lossless queues configured depends on the buffer. The default
number of PFC queues in the system is one.
Data Center Bridging (DCB) 302