dcb(8) — Linux manual page


DCB(8)                            Linux                           DCB(8)

NAME         top

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

SYNOPSIS         top

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

       dcb [ -force ] -batch filename

       dcb [ OPTIONS ] help

OPTIONS         top

       -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         top

       app    - Configuration of application priority table

       buffer - Configuration of port buffers

       ets    - Configuration of ETS (Enhanced Transmission Selection)

              - Configuration of per-TC maximum transmit rate

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

COMMANDS         top

       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.


       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 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         top

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

SEE ALSO         top

       dcb-app(8), dcb-apptrust(8), dcb-buffer(8), dcb-ets(8),
       dcb-maxrate(8), dcb-pfc(8), dcb-rewr(8)

REPORTING BUGS         top

       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         top

       Petr Machata <me@pmachata.org>

COLOPHON         top

       This page is part of the iproute2 (utilities for controlling
       TCP/IP networking and traffic) project.  Information about the
       project can be found at 
       If you have a bug report for this manual page, send it to
       netdev@vger.kernel.org, shemminger@osdl.org.  This page was
       obtained from the project's upstream Git repository
       ⟨https://git.kernel.org/pub/scm/network/iproute2/iproute2.git⟩ on
       2023-12-22.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-12-20.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

iproute2                     19 October 2020                      DCB(8)

Pages that refer to this page: dcb-app(8)dcb-apptrust(8)dcb-buffer(8)dcb-dcbx(8)dcb-ets(8)dcb-maxrate(8)dcb-pfc(8)dcb-rewr(8)