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.

SEE ALSO

       dcb(8)

REPORTING BUGS

       Report any bugs to the Network Developers mailing list <netdev@vger.kernel.org> where the
       development and maintenance is primarily done.  You do not have to be subscribed to the
       list to send a message there.

AUTHOR

       Petr Machata <me@pmachata.org>