Administrator Guide

Committed and peak burst size is in kilobytes. Default is 50. The range is from 0 to 10000.
The pfc on command enables priority-based flow control.
3. Specify the dot1p priority-to-priority group mapping for each priority.
priority-pgid dot1p0_group_num dot1p1_group_num ...dot1p7_group_num
Priority group range is from 0 to 7. All priorities that map to the same queue must be in the same priority group.
Leave a space between each priority group number. For example: priority-pgid 0 0 0 1 2 4 4 4 in which priority group 0 maps to dot1p
priorities 0, 1, and 2; priority group 1 maps to dot1p priority 3; priority group 2 maps to dot1p priority 4; priority group 4 maps to dot1p
priorities 5, 6, and 7.
Dell Networking OS Behavior: 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 Type, Length, Value (TLV) are supported. DCBx
also validates PFC configurations that are received in TLVs from peer devices.
NOTE: You cannot enable PFC and link-level flow control at the same time on an interface.
Dell Networking OS does not support MACsec Bypass Capability (MBC).
NOTE: We recommend that you do not use the dcb-policy input, dcb-policy output, dcb-input, dcb-output,
and priority-group commands as those are removed from Release 9.6.(0.0).
Configuring Lossless Queues
DCB also supports the manual configuration of lossless queues on an interface when PFC mode is turned off.
Prerequisite: A DCB with PFC configuration is applied to the interface with the following conditions:
• PFC mode is off (no pfc mode on).
• No PFC priority classes are configured (no pfc priority priority-range).
The configuration of no-drop queues provides flexibility for ports on which PFC is not needed but lossless traffic should egress from the
interface.
Lossless traffic egresses out the no-drop queues. Ingress dot1p traffic from PFC-enabled interfaces is automatically mapped to the no-
drop egress queues.
1. Enter INTERFACE Configuration mode.
CONFIGURATION mode
interface type slot/port
2. Configure the port queues that will still function as no-drop queues for lossless traffic.
INTERFACE mode
pfc no-drop queues queue-range
For the dot1p-queue assignments, refer to the dot1p Priority-Queue Assignment table.
The maximum number of lossless queues globally supported on the switch is two.
The default: No lossless queues are configured.
NOTE: Dell Networking OS Behavior: By default, no lossless queues are configured on a port.
A limit of 4 lossless queues is supported on a port. If the amount of priority traffic that you configure to be paused exceeds the 4 lossless
queues, an error message displays.
Any pfc-dot1p priorities configured on a given interface need not be the same across the system, until the total lossless queues configured
on all the ports does not exceed the maximum lossless queues configured globally. For example, one of the Te/Fo interfaces can have pfc-
dot1p priorities as 2 and 3. Whereas, the other Te/Fo interface(s) can have its pfc-dot1p priorities as 4 and 5.
It is the user responsibility to have symmetric PFC configurations on the interfaces involved in a particular PFC-enabled traffic-flow to
obtain lossless behavior.
Configuring Enhanced Transmission Selection
ETS provides a way to optimize bandwidth allocation to outbound 802.1p classes of converged Ethernet traffic.
Different traffic types have different service needs. Using ETS, you can create groups within an 802.1p priority class to configure different
treatment for traffic with different bandwidth, latency, and best-effort needs.
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Data Center Bridging (DCB)