DCB(8)                                                         Linux                                                         DCB(8)

NAME
       dcb - show / manipulate DCB (Data Center Bridging) settings

SYNOPSIS
       dcb [ OPTIONS ] { app | buffer | ets | maxrate | pfc } { COMMAND | help }

       dcb [ -force ] -batch filename

       dcb [ OPTIONS ] help

OPTIONS
       -n, --netns <NETNS>
              switches dcb to the specified network namespace NETNS.

       -V, --Version
              Print the version of the dcb utility and exit.

       -b, --batch <FILENAME>
              Read commands from provided file or standard input and invoke them. First failure will cause termination of dcb.

       -f, --force
              Don't terminate dcb on errors in batch mode. If there were any errors during execution of the commands, the applica‐
              tion return code will be non zero.

       -i, --iec
              When showing rates, use ISO/IEC 1024-based prefixes (Ki, Mi, Bi) instead of the 1000-based ones (K, M, B).

       -j, --json
              Generate JSON output.

       -N, --Numeric
              If the subtool in question translates numbers to symbolic names in some way, suppress this translation.

       -p, --pretty
              When combined with -j generate a pretty JSON output.

       -s, --statistics
              If the object in question contains any statistical counters, shown them as part of the "show" output.

OBJECTS
       app    - Configuration of application priority table

       buffer - Configuration of port buffers

       ets    - Configuration of ETS (Enhanced Transmission Selection)

       maxrate
              - Configuration of per-TC maximum transmit rate

       pfc    - Configuration of PFC (Priority-based Flow Control)

COMMANDS
       A COMMAND specifies the action to perform on the object. The set of possible actions depends on the object type. As a rule,
       it is possible to show objects and to invoke topical help, which prints a list of available commands and argument syntax
       conventions.

ARRAY PARAMETERS
       Like commands, specification of parameters is in the domain of individual objects (and their commands) as well. However,
       much of the DCB interface revolves around arrays of fixed size that specify one value per some key, such as per traffic
       class or per priority. There is therefore a single syntax for adjusting elements of these arrays. It consists of a series of
       KEY:VALUE pairs, where the meaning of the individual keys and values depends on the parameter.

       The elements are evaluated in order from left to right, and the latter ones override the earlier ones. The elements that are
       not specified on the command line are queried from the kernel and their current value is retained.

       As an example, take a made-up parameter tc-juju, which can be set to charm traffic in a given TC with either good luck or
       bad luck. KEY can therefore be 0..7 (as is usual for TC numbers in DCB), and VALUE either of none, good, and bad. An example
       of changing a juju value of TCs 0 and 7, while leaving all other intact, would then be:

       # dcb foo set dev eth0 tc-juju 0:good 7:bad

       A special key, all, is recognized which sets the same value to all array elements. This can be combined with the usual sin‐
       gle-element syntax. E.g. in the following, the juju of all keys is set to none, except 0 and 7, which have other values:

       # dcb foo set dev eth0 tc-juju all:none 0:good 7:bad

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

SEE ALSO
       dcb-app(8), dcb-buffer(8), dcb-ets(8), dcb-maxrate(8), dcb-pfc(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>

iproute2                                                  19 October 2020                                                    DCB(8)