Administrator Guide

Data Center Bridging (DCB)
Topics:
• Enabling Data Center Bridging
• Ethernet Enhancements in Data Center Bridging
• QoS dot1p Traffic Classification and Queue Assignment
• SNMP Support for PFC and Buffer Statistics Tracking
• DCB Maps and its Attributes
• Data Center Bridging: Default Configuration
• Configuration Notes: PFC and ETS in a DCB Map
• Configuring Priority-Based Flow Control
• Configuring Enhanced Transmission Selection
• Configure a DCBx Operation
• Verifying the DCB Configuration
• Performing PFC Using DSCP Bits Instead of 802.1p Bits
• PFC and ETS Configuration Examples
• Using PFC and ETS to Manage Data Center Traffic
• Priority-Based Flow Control Using Dynamic Buffer Method
• Configuring the Dynamic Buffer Method
Enabling Data Center Bridging
Data center bridging supports converged enhanced Ethernet (CEE) in a data center network. By default, DCB is disabled. It
must be enabled to support CEE.
NOTE:
DCB is not supported on the Port Extender (PE) ports and cascade ports. For information about PE ports, see
Interface Types and Port Extenders.
● Priority-based flow control
● Enhanced transmission selection
● Data center bridging exchange protocol
● FCoE initialization protocol (FIP) snooping
DCB processes virtual local area network (VLAN)-tagged packets and dot1p priority values. Untagged packets are treated with a
dot1p priority of 0.
To enable DCB, enter the following command.
Enable DCB.
CONFIGURATION mode
dcb enable
By default, PFC is enabled for 2 lossless queues when use the dcb enable command. To configure, 3-4 lossless queues use the
following syntax:
Dell(conf)#dcb enable pfc-queues ?
<1-4> Number of PFC lossless queues(default=2)
dcb-map linecard 0 backplane all <name>
dcb-map linecard all backplane all <name>
NOTE:
Dell Networking OS Behavior: DCB is not supported if you enable link-level flow control on one or more
interfaces. For more information, refer to Ethernet Pause Frames.
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