1DCB-ETS(8)                           Linux                          DCB-ETS(8)
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3
4

NAME

6       dcb-app - show / manipulate application priority table of the DCB (Data
7       Center Bridging) subsystem
8

SYNOPSIS

10       dcb [ OPTIONS ] app { COMMAND | help }
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12
13       dcb app  {  show  |  flush  }  dev DEV [ default-prio ] [ ethtype-prio
14               ] [ stream-port-prio ] [ dgram-port-prio ] [ port-prio ] [
15               dscp-prio ]
16
17       dcb ets  {  add  |  del  |  replace  }  dev DEV [ default-prio PRIO-
18               LIST ] [ ethtype-prio ET-MAP ] [ stream-port-prio PORT-MAP ] [
19               dgram-port-prio PORT-MAP ] [ port-prio PORT-MAP ] [ dscp-prio
20               DSCP-MAP ]
21
22       PRIO-LIST := [ PRIO-LIST ] PRIO
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24       ET-MAP := [ ET-MAP ] ET-MAPPING
25
26       ET-MAPPING := ET:PRIO
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28       PORT-MAP := [ PORT-MAP ] PORT-MAPPING
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30       PORT-MAPPING := PORT:PRIO
31
32       DSCP-MAP := [ DSCP-MAP ] DSCP-MAPPING
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34       DSCP-MAPPING := { DSCP | all }:PRIO
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36       ET := { 0x600 .. 0xffff }
37
38       PORT := { 1 .. 65535 }
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40       DSCP := { 0 .. 63 }
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42       PRIO := { 0 .. 7 }
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44

DESCRIPTION

46       dcb app is used to configure APP table, or application priority table
47       in the DCB (Data Center Bridging) subsystem. The APP table is used to
48       assign priority to traffic based on value in one of several headers:
49       EtherType, L4 destination port, or DSCP. It also allows configuration
50       of port-default priority that is chosen if no other prioritization rule
51       applies.
52
53       DCB APP entries are 3-tuples of selector, protocol ID, and priority.
54       Selector is an enumeration that picks one of the prioritization name‐
55       spaces. Currently it mostly corresponds to configurable parameters de‐
56       scribed below. Protocol ID is a value in the selector namespace. E.g.
57       for EtherType selector, protocol IDs are the individual EtherTypes, for
58       DSCP they are individual code points. The priority is the priority that
59       should be assigned to traffic that matches the selector and protocol
60       ID.
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62       The APP table is a set of DCB APP entries. The only requirement is that
63       duplicate entries are not added. Notably, it is valid to have conflict‐
64       ing priority assignment for the same selector and protocol ID. For ex‐
65       ample, the set of two APP entries (DSCP, 10, 1) and (DSCP, 10, 2),
66       where packets with DSCP of 10 should get priority of both 1 and 2, form
67       a well-defined APP table. The dcb app tool allows low-level management
68       of the app table by adding and deleting individual APP 3-tuples through
69       add and del commands. On the other other hand, the command replace does
70       what one would typically want in this situation--first adds the new
71       configuration, and then removes the obsolete one, so that only one pri‐
72       oritization is in effect for a given selector and protocol ID.
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74

COMMANDS

76       show   Display all entries with a given selector. When no selector is
77              given, shows all APP table entries categorized per selector.
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80       flush  Remove all entries with a given selector. When no selector is
81              given, removes all APP table entries.
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83
84       add
85       del    Add and, respectively, remove individual APP 3-tuples to and
86              from the DCB APP table.
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88
89       replace
90              Take the list of entries mentioned as parameter, and add those
91              that are not present in the APP table yet. Then remove those en‐
92              tries, whose selector and protocol ID have been mentioned as pa‐
93              rameter, but not with the exact same priority. This has the ef‐
94              fect of, for the given selector and protocol ID, causing that
95              the table only contains the priority (or priorities) given as
96              parameter.
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98

PARAMETERS

100       The following table shows parameters in a way that they would be used
101       with add, del and replace commands. For show and flush, the parameter
102       name is to be used as a simple keyword without further arguments.
103
104
105       default-prio PRIO-LIST
106              The priority to be used for traffic the priority of which is
107              otherwise unspecified. The argument is a list of individual pri‐
108              orities. Note that default-prio rules are configured as triplets
109              (EtherType, 0, PRIO).  dcb app translates these rules to the
110              symbolic name default-prio and back.
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112
113       ethtype-prio ET-MAP
114              ET-MAP uses the array parameter syntax, see dcb(8) for details.
115              Keys are EtherType values. Values are priorities to be assigned
116              to traffic with the matching EtherType.
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118
119       stream-port-prio PORT-MAP
120       dgram-port-prio PORT-MAP
121       port-prio PORT-MAP
122              PORT-MAP uses the array parameter syntax, see dcb(8) for de‐
123              tails. Keys are L4 destination port numbers that match on, re‐
124              spectively, TCP and SCTP traffic, UDP and DCCP traffic, and ei‐
125              ther of those. Values are priorities that should be assigned to
126              matching traffic.
127
128
129       dscp-prio DSCP-MAP
130              DSCP-MAP uses the array parameter syntax, see dcb(8) for de‐
131              tails. Keys are DSCP points, values are priorities assigned to
132              traffic with matching DSCP. DSCP points can be written either
133              direcly as numeric values, or using symbolic names specified in
134              /etc/iproute2/rt_dsfield (however note that that file specifies
135              full 8-bit dsfield values, whereas dcb app will only use the
136              higher six bits).  dcb app show will similarly format DSCP val‐
137              ues as symbolic names if possible. The command line option -N
138              turns the show translation off.
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140

EXAMPLE & USAGE

142       Prioritize traffic with DSCP 0 to priority 0, 24 to 3 and 48 to 6:
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145       # dcb app add dev eth0 dscp-prio 0:0 24:3 48:6
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147       Add another rule to configure DSCP 24 to priority 2 and show the re‐
148       sult:
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150
151       # dcb app add dev eth0 dscp-prio 24:2
152       # dcb app show dev eth0 dscp-prio
153       dscp-prio 0:0 CS3:2 CS3:3 CS6:6
154       # dcb -N app show dev eth0 dscp-prio
155       dscp-prio 0:0 24:2 24:3 48:6
156
157       Reconfigure the table so that the only rule for DSCP 24 is for assign‐
158       ment of priority 4:
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160
161       # dcb app replace dev eth0 dscp-prio 24:4
162       # dcb app show dev eth0 dscp-prio
163       dscp-prio 0:0 24:4 48:6
164
165       Flush all DSCP rules:
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167
168       # dcb app flush dev eth0 dscp-prio
169       # dcb app show dev eth0 dscp-prio
170       (nothing)
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EXIT STATUS

174       Exit status is 0 if command was successful or a positive integer upon
175       failure.
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177

SEE ALSO

179       dcb(8)
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181

REPORTING BUGS

183       Report any bugs to the Network Developers mailing list <net‐
184       dev@vger.kernel.org> where the development and maintenance is primarily
185       done.  You do not have to be subscribed to the list to send a message
186       there.
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188

AUTHOR

190       Petr Machata <me@pmachata.org>
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194iproute2                        6 December 2020                     DCB-ETS(8)
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