White Papers

12 Data Center Bridging (DCB).....................................................................................................................250
Ethernet Enhancements in Data Center Bridging..................................................................................................... 250
Priority-Based Flow Control....................................................................................................................................251
Enhanced Transmission Selection..........................................................................................................................252
Data Center Bridging Exchange Protocol (DCBx)...............................................................................................253
Data Center Bridging in a Trac Flow.................................................................................................................. 254
Enabling Data Center Bridging.....................................................................................................................................254
DCB Maps and its Attributes................................................................................................................................. 255
Data Center Bridging: Default Conguration..............................................................................................................256
Conguring Priority-Based Flow Control....................................................................................................................256
Conguring Lossless Queues..................................................................................................................................257
Conguring PFC in a DCB Map................................................................................................................................... 258
PFC Conguration Notes....................................................................................................................................... 258
PFC Prerequisites and Restrictions.......................................................................................................................259
Applying a DCB Map on a Port....................................................................................................................................259
Conguring PFC without a DCB Map.........................................................................................................................260
Conguring Lossless QueuesExample:..................................................................................................................260
Priority-Based Flow Control Using Dynamic Buer Method....................................................................................262
Pause and Resume of Trac..................................................................................................................................262
Buer Sizes for Lossless or PFC Packets............................................................................................................ 262
Behavior of Tagged Packets.........................................................................................................................................263
Conguration Example for DSCP and PFC Priorities................................................................................................263
Using PFC to Manage Converged Ethernet Trac...................................................................................................264
Congure Enhanced Transmission Selection..............................................................................................................264
ETS Prerequisites and Restrictions....................................................................................................................... 264
Creating an ETS Priority Group............................................................................................................................. 265
ETS Operation with DCBx......................................................................................................................................266
Conguring Bandwidth Allocation for DCBx CIN................................................................................................ 266
Conguring ETS in a DCB Map..............................................................................................................................267
Hierarchical Scheduling in ETS Output Policies......................................................................................................... 268
Using ETS to Manage Converged Ethernet Trac...................................................................................................269
Applying DCB Policies in a Switch Stack....................................................................................................................269
Congure a DCBx Operation........................................................................................................................................269
DCBx Operation.......................................................................................................................................................269
DCBx Port Roles...................................................................................................................................................... 270
DCB Conguration Exchange................................................................................................................................. 271
Conguration Source Election.................................................................................................................................271
Propagation of DCB Information............................................................................................................................272
Auto-Detection and Manual Conguration of the DCBx Version.......................................................................272
DCBx Example..........................................................................................................................................................273
DCBx Prerequisites and Restrictions.....................................................................................................................273
Conguring DCBx.....................................................................................................................................................274
Verifying the DCB Conguration..................................................................................................................................277
QoS dot1p Trac Classication and Queue Assignment.......................................................................................... 287
Conguring the Dynamic Buer Method................................................................................................................... 288
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