Configuration manual

Dell Networking OS Behavior: If you configure 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 buffer
size that is created must be greater than or equal to the buffer size required for PFC-enabled ports and
lossless queues on the switch.
For the PFC buffer configuration to take effect, you must reload the stack or a specified stack unit (use
the reload command at EXEC Privilege level).
If you configure the PFC buffer on all stack units, delete the startup configuration 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.
Configure 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.
For example, storage traffic is sensitive to frame loss; interprocess communication (IPC) traffic is latency-
sensitive. ETS allows different traffic 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 configure 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 traffic classes.
3. Configure 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 configure ETS bandwidth allocation or queue
scheduling and apply a QoS ETS output policy on an interface.
• Configuring 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 Configuring DCBx) or CEE as a port
version where CNA supports CEE and DUT port versions in AUTO or CEE mode.
• When allocating bandwidth or configuring a queue scheduler for dot1p priorities in a priority group on
a DCBx CIN interface, take into account the CIN bandwidth allocation (refer to Configuring
Bandwidth Allocation for DCBx CIN) and dot1p-queue mapping (QoS dot1p Traffic Classification and
Queue Assignment).
• Although an ETS output policy does not support WRED, ECN, rate shaping, and rate limiting because
DCBx does not negotiate these parameters with peer devices, you can apply a QoS output policy with
WRED and/or rate shaping on a DCBx CIN-enabled interface (refer to Configuring Port-Based Rate
Shaping and Weighted Random Early Detection). In this case, the WRED or rate shaping configuration
Data Center Bridging (DCB)
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