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DCB-ETS(8)                           Linux                          DCB-ETS(8)
NAME
       dcb-app - show / manipulate application priority table of the DCB (Data
       Center Bridging) subsystem
SYNOPSIS
       dcb [ OPTIONS ] app { COMMAND | help }
       dcb app  {  show  |  flush  }  dev DEV [ default-prio ] [ ethtype-prio
               ] [ stream-port-prio ] [ dgram-port-prio ] [ port-prio ] [
               dscp-prio ] [ pcp-prio ]
       dcb ets  {  add  |  del  |  replace  }  dev DEV [ default-prio PRIO-
               LIST ] [ ethtype-prio ET-MAP ] [ stream-port-prio PORT-MAP ] [
               dgram-port-prio PORT-MAP ] [ port-prio PORT-MAP ] [ dscp-prio
               DSCP-MAP ] [ pcp-prio PCP-MAP ]
       PRIO-LIST := [ PRIO-LIST ] PRIO
       ET-MAP := [ ET-MAP ] ET-MAPPING
       ET-MAPPING := ET:PRIO
       PORT-MAP := [ PORT-MAP ] PORT-MAPPING
       PORT-MAPPING := PORT:PRIO
       DSCP-MAP := [ DSCP-MAP ] DSCP-MAPPING
       DSCP-MAPPING := { DSCP | all }:PRIO
       PCP-MAP := [ PCP-MAP ] PCP-MAPPING
       PCP-MAPPING := PCP:PRIO
       ET := { 0x600 .. 0xffff }
       PORT := { 1 .. 65535 }
       DSCP := { 0 .. 63 }
       PCP := { 0(nd/de) .. 7(nd/de) }
       PRIO := { 0 .. 7 }
DESCRIPTION
       dcb app is used to configure APP table, or application priority table
       in the DCB (Data Center Bridging) subsystem. The APP table is used to
       assign priority to traffic based on value in one of several headers:
       EtherType, L4 destination port, or DSCP. It also allows configuration
       of port-default priority that is chosen if no other prioritization rule
       applies.
       DCB APP entries are 3-tuples of selector, protocol ID, and priority.
       Selector is an enumeration that picks one of the prioritization names-
       paces. Currently it mostly corresponds to configurable parameters
       described below. Protocol ID is a value in the selector namespace. E.g.
       for EtherType selector, protocol IDs are the individual EtherTypes, for
       DSCP they are individual code points. The priority is the priority that
       should be assigned to traffic that matches the selector and protocol
       ID.
       The APP table is a set of DCB APP entries. The only requirement is that
       duplicate entries are not added. Notably, it is valid to have conflict-
       ing priority assignment for the same selector and protocol ID. For
       example, the set of two APP entries (DSCP, 10, 1) and (DSCP, 10, 2),
       where packets with DSCP of 10 should get priority of both 1 and 2, form
       a well-defined APP table. The dcb app tool allows low-level management
       of the app table by adding and deleting individual APP 3-tuples through
       add and del commands. On the other other hand, the command replace does
       what one would typically want in this situation--first adds the new
       configuration, and then removes the obsolete one, so that only one pri-
       oritization is in effect for a given selector and protocol ID.
COMMANDS
       show   Display all entries with a given selector. When no selector is
              given, shows all APP table entries categorized per selector.
       flush  Remove all entries with a given selector. When no selector is
              given, removes all APP table entries.
       add
       del    Add and, respectively, remove individual APP 3-tuples to and
              from the DCB APP table.
       replace
              Take the list of entries mentioned as parameter, and add those
              that are not present in the APP table yet. Then remove those
              entries, whose selector and protocol ID have been mentioned as
              parameter, but not with the exact same priority. This has the
              effect of, for the given selector and protocol ID, causing that
              the table only contains the priority (or priorities) given as
              parameter.
PARAMETERS
       The following table shows parameters in a way that they would be used
       with add, del and replace commands. For show and flush, the parameter
       name is to be used as a simple keyword without further arguments.
       default-prio PRIO-LIST
              The priority to be used for traffic the priority of which is
              otherwise unspecified. The argument is a list of individual pri-
              orities. Note that default-prio rules are configured as triplets
              (EtherType, 0, PRIO).  dcb app translates these rules to the
              symbolic name default-prio and back.
       ethtype-prio ET-MAP
              ET-MAP uses the array parameter syntax, see dcb(8) for details.
              Keys are EtherType values. Values are priorities to be assigned
              to traffic with the matching EtherType.
       stream-port-prio PORT-MAP
       dgram-port-prio PORT-MAP
       port-prio PORT-MAP
              PORT-MAP uses the array parameter syntax, see dcb(8) for
              details. Keys are L4 destination port numbers that match on,
              respectively, TCP and SCTP traffic, UDP and DCCP traffic, and
              either of those. Values are priorities that should be assigned
              to matching traffic.
       dscp-prio DSCP-MAP
              DSCP-MAP uses the array parameter syntax, see dcb(8) for
              details. Keys are DSCP points, values are priorities assigned to
              traffic with matching DSCP. DSCP points can be written either
              directly as numeric values, or using symbolic names specified in
              /etc/iproute2/rt_dsfield (however note that that file specifies
              full 8-bit dsfield values, whereas dcb app will only use the
              higher six bits).  dcb app show will similarly format DSCP val-
              ues as symbolic names if possible. The command line option -N
              turns the show translation off.
       pcp-prio PCP-MAP
              PCP-MAP uses the array parameter syntax, see dcb(8) for details.
              Keys are PCP/DEI. Values are priorities assigned to traffic with
              matching PCP/DEI. PCP/DEI values are written as a combination of
              numeric- and symbolic values, to accommodate for both. PCP
              always in numerical form e.g 0 .. 7 and DEI in symbolic form e.g
              'de' (drop-eligible), indicating that the DEI bit is 1 or 'nd'
              (not-drop-eligible), indicating that the DEI bit is 0.  In com-
              bination 2de:1 translates to a mapping of PCP=2 and DEI=1 to
              priority 1.
EXAMPLE & USAGE
       Prioritize traffic with DSCP 0 to priority 0, 24 to 3 and 48 to 6:
       # dcb app add dev eth0 dscp-prio 0:0 24:3 48:6
       Add another rule to configure DSCP 24 to priority 2 and show the
       result:
       # dcb app add dev eth0 dscp-prio 24:2
       # dcb app show dev eth0 dscp-prio
       dscp-prio 0:0 CS3:2 CS3:3 CS6:6
       # dcb -N app show dev eth0 dscp-prio
       dscp-prio 0:0 24:2 24:3 48:6
       Reconfigure the table so that the only rule for DSCP 24 is for assign-
       ment of priority 4:
       # dcb app replace dev eth0 dscp-prio 24:4
       # dcb app show dev eth0 dscp-prio
       dscp-prio 0:0 24:4 48:6
       Flush all DSCP rules:
       # dcb app flush dev eth0 dscp-prio
       # dcb app show dev eth0 dscp-prio
       (nothing)
       Add a rule to map traffic with PCP 1 and DEI 0 to priority 1 and PCP 2
       and DEI 1 to priority 2:
       # dcb app add dev eth0 pcp-prio 1nd:1 2de:2
       # dcb app show dev eth0 pcp-prio
       pcp-prio 1nd:1 2de:2
EXIT STATUS
       Exit status is 0 if command was successful or a positive integer upon
       failure.
SEE ALSO
       dcb(8)
REPORTING BUGS
       Report any bugs to the Network Developers mailing list <net-
       dev AT vger.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 AT pmachata.org>
iproute2                        6 December 2020                     DCB-ETS(8)