Administrator Guide

CONFIGURATION mode
[no] dcb stack-unit all pfc-buffering pfc-port {1-56} pfc-queues {1-2}
By default, the PFC buer is enabled on all ports on the stack unit.
• Congure the PFC buer for all port pipes in a specied stack unit by specifying the port-pipe number, number of PFC-enabled
ports, and number of congured lossless queues.
CONFIGURATION mode
[no] dcb stack-unit stack-unit-id [port-set port-set-id] pfc-buffering pfc-ports {1-56}
pfc-queues {1-2}
Valid stack-unit IDs are 0 to 5.
The only valid port-set ID (port-pipe number) is 0.
Dell Networking OS Behavior: If you congure PFC on a 40GbE port, count the 40GbE port as four PFC-enabled ports in the pfc-
port number you enter in the command syntax.
To achieve lossless PFC operation, the PFC port count and queue number used for the reserved buer size that is created must be
greater than or equal to the buer size required for PFC-enabled ports and lossless queues on the switch.
For the PFC buer conguration to take eect, you must reload the stack or a specied stack unit (use the reload command at
EXEC Privilege level).
If you congure the PFC buer on all stack units, delete the startup conguration on both the master and standby, and reload the
stack, the new master (previously standby) generates the following syslog message for each stack unit when it boots up:
PFC_BUFFER_CONFIG_CHANGED is generated for all stack units.
Congure Enhanced Transmission Selection
ETS provides a way to optimize bandwidth allocation to outbound 802.1p classes of converged Ethernet trac.
Dierent trac types have dierent service needs. Using ETS, you can create groups within an 802.1p priority class to congure
dierent treatment for trac with dierent bandwidth, latency, and best-eort needs.
For example, storage trac is sensitive to frame loss; interprocess communication (IPC) trac is latency-sensitive. ETS allows
dierent trac types to coexist without interruption in the same converged link by:
• Allocating a guaranteed share of bandwidth to each priority group.
• Allowing each group to exceed its minimum guaranteed bandwidth if another group is not fully using its allotted bandwidth.
To congure ETS and apply an ETS output policy to an interface, you must:
1. Create a Quality of Service (QoS) output policy with ETS scheduling and bandwidth allocation settings.
2. Create a priority group of 802.1p trac classes.
3. Congure a DCB output policy in which you associate a priority group with a QoS ETS output policy.
4. Apply the DCB output policy to an interface.
ETS Prerequisites and Restrictions
The following prerequisites and restrictions apply when you congure ETS bandwidth allocation or queue scheduling and apply a QoS
ETS output policy on an interface.
• Conguring ETS bandwidth allocation or a queue scheduler for dot1p priorities in a priority group is applicable if the DCBx version
used on a port is CIN (refer to Conguring DCBx) or CEE as a port version where CNA supports CEE and DUT port versions in
AUTO or CEE mode.
• When allocating bandwidth or conguring a queue scheduler for dot1p priorities in a priority group on a DCBx CIN interface, take
into account the CIN bandwidth allocation (refer to Conguring Bandwidth Allocation for DCBx CIN) and dot1p-queue mapping
(QoS dot1p Trac Classication and Queue Assignment).
Data Center Bridging (DCB)
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