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 pos-
sible 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 avail-
able commands and argument syntax conventions.
ARRAY PARAMETERS
Like commands, specification of parameters is in the domain of individ-
ual objects (and their commands) as well. However, much of the DCB in-
terface 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-apptrust(8), dcb-buffer(8), dcb-ets(8), dcb-maxrate(8),
dcb-pfc(8), dcb-rewr(8)
REPORTING BUGS
Report any bugs to the Network Developers mailing list <netdev@vger.ker-
nel.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)
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