man > dcb(8)

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 application 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 parame‐
       ter.

       The elements are evaluated in order from left to right, and the latter ones override the ear‐
       lier ones. The elements that are not specified on the command line are queried from the  ker‐
       nel 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 single-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 AT vger.org> where the de‐
       velopment and maintenance is primarily done.  You do not have to be subscribed to the list to
       send a message there.


AUTHOR
       Petr Machata <me AT pmachata.org>

iproute2                                   19 October 2020                                    DCB(8)