Users Guide

Data Center Bridging (DCB)
Data center bridging (DCB) refers to a set of enhancements to Ethernet local area networks used in data center environments, particularly
with clustering and storage area networks.
Topics:
• Ethernet Enhancements in Data Center Bridging
• Enabling Data Center Bridging
• Data Center Bridging: Default Conguration
• Conguring Priority-Based Flow Control
• Conguring PFC in a DCB Map
• Applying a DCB Map on a Port
• Conguring PFC without a DCB Map
• Priority-Based Flow Control Using Dynamic Buer Method
• Shared headroom for lossless or PFC packets
• Behavior of Tagged Packets
• SNMP Support for PFC and Buer Statistics Tracking
• Performing PFC Using DSCP Bits Instead of 802.1p Bits
• Conguration Example for DSCP and PFC Priorities
• Using PFC to Manage Converged Ethernet Trac
• Generation of PFC for a Priority for Untagged Packets
• Congure Enhanced Transmission Selection
• Hierarchical Scheduling in ETS Output Policies
• Using ETS to Manage Converged Ethernet Trac
• Applying DCB Policies in a Switch Stack
• Congure a DCBx Operation
• Verifying the DCB Conguration
• QoS dot1p Trac Classication and Queue Assignment
• Conguring the Dynamic Buer Method
• Sample DCB Conguration
Ethernet Enhancements in Data Center Bridging
The following section describes DCB.
The device supports the following DCB features:
• Priority-based ow control (PFC)
• Enhanced transmission selection (ETS)
To congure PFC, ETS, and for DCB, refer to Sample DCB Conguration for the CLI congurations.
DCB refers to a set of IEEE Ethernet enhancements that provide data centers with a single, robust, converged network to support multiple
trac types, including local area network (LAN), server, and storage trac. Through network consolidation, DCB results in reduced
operational cost, simplied management, and easy scalability by avoiding the need to deploy separate application-specic networks.
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246 Data Center Bridging (DCB)