{
    "mode": "man",
    "parameter": "dcb-pfc",
    "section": "8",
    "url": "https://www.chedong.com/phpMan.php/man/dcb-pfc/8/json",
    "generated": "2026-06-15T13:50:47Z",
    "synopsis": "dcb [ OPTIONS ] pfc { COMMAND | help }\ndcb pfc show dev DEV [ pfc-cap ] [ prio-pfc ] [ macsec-bypass ] [ delay ] [ requests ] [ in‐‐\ndications ]\ndcb pfc set dev DEV [ prio-pfc PFC-MAP ] [ macsec-bypass { on | off } ] [ delay INTEGER ]\nPFC-MAP := [ PFC-MAP ] PFC-MAPPING\nPFC-MAPPING := { PRIO | all }:{ on | off }\nPRIO := { 0 .. 7 }",
    "sections": {
        "NAME": {
            "content": "dcb-pfc  - show / manipulate PFC (Priority-based Flow Control) settings of the DCB (Data Cen‐\nter Bridging) subsystem\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "dcb [ OPTIONS ] pfc { COMMAND | help }\n\n\ndcb pfc show dev DEV [ pfc-cap ] [ prio-pfc ] [ macsec-bypass ] [ delay ] [ requests ] [ in‐‐\ndications ]\n\ndcb pfc set dev DEV [ prio-pfc PFC-MAP ] [ macsec-bypass { on | off } ] [ delay INTEGER ]\n\nPFC-MAP := [ PFC-MAP ] PFC-MAPPING\n\nPFC-MAPPING := { PRIO | all }:{ on | off }\n\nPRIO := { 0 .. 7 }\n\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "dcb pfc is used to configure Priority-based Flow Control attributes through Linux DCB (Data\nCenter Bridging) interface. PFC permits marking flows with a certain priority as lossless,\nand holds related configuration, as well as PFC counters.\n\n",
            "subsections": []
        },
        "PARAMETERS": {
            "content": "For read-write parameters, the following describes only the write direction, i.e. as used\nwith the set command. For the show command, the parameter name is to be used as a simple key‐\nword without further arguments. This instructs the tool to show the value of a given parame‐\nter. When no parameters are given, the tool shows the complete PFC configuration.\n\n",
            "subsections": [
                {
                    "name": "pfc-cap",
                    "content": "A read-only property that shows the number of traffic classes that may simultaneously\nsupport PFC.\n\n"
                },
                {
                    "name": "requests",
                    "content": "A read-only count of the sent PFC frames per traffic class. Only shown when -s is\ngiven, or when requested explicitly.\n\n"
                },
                {
                    "name": "indications",
                    "content": "A read-only count of the received PFC frames per traffic class. Only shown when -s is\ngiven, or when requested explicitly.\n\n\nmacsec-bypass { on | off }\nWhether the sending station is capable of bypassing MACsec processing when MACsec is\ndisabled.\n\n\nprio-pfc PFC-MAP\nPFC-MAP uses the array parameter syntax, see dcb(8) for details. Keys are priorities,\nvalues are on / off indicators of whether PFC is enabled for a given priority.\n\n\ndelay INTEGER\nThe allowance made for round-trip propagation delay of the link in bits.  The value\nshall be 0..65535.\n\n"
                },
                {
                    "name": "EXAMPLE & USAGE",
                    "content": "Enable PFC on priorities 6 and 7, leaving the rest intact:\n\n\n# dcb pfc set dev eth0 prio-pfc 6:on 7:on\n\nDisable PFC of all priorities except 6 and 7, and configure delay to 4096 bits:\n\n\n# dcb pfc set dev eth0 prio-pfc all:off 6:on 7:on delay 0x1000\n\nShow what was set:\n\n\n# dcb pfc show dev eth0\npfc-cap 8 macsec-bypass off delay 4096\nprio-pfc 0:off 1:off 2:off 3:off 4:off 5:off 6:on 7:on\n\n"
                }
            ]
        },
        "EXIT STATUS": {
            "content": "Exit status is 0 if command was successful or a positive integer upon failure.\n\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "dcb(8)\n\n",
            "subsections": []
        },
        "REPORTING BUGS": {
            "content": "Report any bugs to the Network Developers mailing list <netdev@vger.kernel.org> where the de‐\nvelopment and maintenance is primarily done.  You do not have to be subscribed to the list to\nsend a message there.\n\n",
            "subsections": []
        },
        "AUTHOR": {
            "content": "Petr Machata <me@pmachata.org>\n\n\n\niproute2                                   31 October 2020                                DCB-PFC(8)",
            "subsections": []
        }
    },
    "summary": "dcb-pfc  - show / manipulate PFC (Priority-based Flow Control) settings of the DCB (Data Cen‐ ter Bridging) subsystem",
    "flags": [],
    "examples": [],
    "see_also": [
        {
            "name": "dcb",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/dcb/8/json"
        }
    ]
}