# dcb-pfc

## NAME



           dcb-pfc - show / manipulate PFC (Priority-based Flow Control)
           settings of the DCB (Data Center Bridging) subsystem
    


## SYNOPSIS



           **dcb**[ _OPTIONS_ ] **pfc**{ _COMMAND_ | _help_ }
    
           **dcb pfc show dev** DEV [ **pfc-cap**] [ **prio-pfc**] [ **macsec-bypass**] [
                   **delay**] [ **requests**] [ **indications**]
    
           **dcb pfc set dev** DEV [ **prio-pfc** _PFC-MAP_ ] [ **macsec-bypass**{ **on** |
                   **off**} ] [ **delay** _INTEGER_ ]
    
           _PFC-MAP_ := [ _PFC-MAP_ ] _PFC-MAPPING_
    
           _PFC-MAPPING_ := { _PRIO_ | **all**}**:**{ **on** | **off**}
    
           _PRIO_ := { **0**.. **7**}
    


## DESCRIPTION



           **dcb pfc** is used to configure Priority-based Flow Control
           attributes through Linux DCB (Data Center Bridging) interface. PFC
           permits marking flows with a certain priority as lossless, and
           holds related configuration, as well as PFC counters.
    


## PARAMETERS



           For read-write parameters, the following describes only the write
           direction, i.e. as used with the **set** command. For the **show**
           command, the parameter name is to be used as a simple keyword
           without further arguments. This instructs the tool to show the
           value of a given parameter. When no parameters are given, the tool
           shows the complete PFC configuration.
    
           **pfc-cap**
                  A read-only property that shows the number of traffic
                  classes that may simultaneously support PFC.
    
           **requests**
                  A read-only count of the sent PFC frames per traffic class.
                  Only shown when -s is given, or when requested explicitly.
    
           **indications**
                  A read-only count of the received PFC frames per traffic
                  class. Only shown when -s is given, or when requested
                  explicitly.
    
           **macsec-bypass**{ **on** | **off**}
                  Whether the sending station is capable of bypassing MACsec
                  processing when MACsec is disabled.
    
           **prio-pfc** _PFC-MAP_
                  _PFC-MAP_ uses the array parameter syntax, see dcb(8) for
                  details. Keys are priorities, values are on / off
                  indicators of whether PFC is enabled for a given priority.
    
           **delay** _INTEGER_
                  The allowance made for round-trip propagation delay of the
                  link in bits.  The value shall be 0..65535.
    


## EXAMPLE & USAGE



           Enable PFC on priorities 6 and 7, leaving the rest intact:
    
           # dcb pfc set dev eth0 prio-pfc 6:on 7:on
    
           Disable PFC of all priorities except 6 and 7, and configure delay
           to 4096 bits:
    
           # dcb pfc set dev eth0 prio-pfc all:off 6:on 7:on delay 0x1000
    
           Show what was set:
    
           # dcb pfc show dev eth0
           pfc-cap 8 macsec-bypass off delay 4096
           prio-pfc 0:off 1:off 2:off 3:off 4:off 5:off 6:on 7:on
    


## EXIT STATUS



           Exit status is 0 if command was successful or a positive integer
           upon failure.
    


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