DCB-PFC(8) Linux DCB-PFC(8)

# [NAME](#NAME)

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

# [SYNOPSIS](#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](#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](#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**](#pfc-cap)

A read-only property that shows the number of traffic classes that may simultaneously support PFC.

[**requests**](#requests)

A read-only count of the sent PFC frames per traffic class. Only shown when -s is given, or when requested explicitly.

[**indications**](#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 }**](#macsec-bypass)

Whether the sending station is capable of bypassing MACsec processing when MACsec is disabled.

[**prio-pfc *PFC-MAP***](#prio-pfc)

*PFC-MAP* uses the array parameter syntax, see [**dcb**(8)](/man/os/iproute2/dcb.8) for details. Keys are priorities, values are on / off indicators of whether PFC is enabled for a given priority.

[**delay *INTEGER***](#delay)

The allowance made for round-trip propagation delay of the link in bits. The value shall be 0..65535.

# [EXAMPLE & USAGE](#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)

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

# [SEE ALSO](#SEE_ALSO)

[**dcb**(8)](/man/os/iproute2/dcb.8)

# [REPORTING BUGS](#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](#AUTHOR)

Petr Machata <me@pmachata.org>

31 October 2020 iproute2

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Document: dcb-pfc(8) from iproute2 7.3.0-r0 (Chainguard OS)
Source: https://kernel.googlesource.com/pub/scm/network/iproute2/iproute2