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 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

       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>