dcb-ets(8)

1DCB-ETS(8)                           Linux                          DCB-ETS(8)
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NAME

6       dcb-ets  - show / manipulate ETS (Enhanced Transmission Selection) set‐
7       tings of the DCB (Data Center Bridging) subsystem
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SYNOPSIS

10       dcb [ OPTIONS ] ets { COMMAND | help }
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13       dcb ets show dev DEV [ willing ] [ ets-cap ] [ cbs ] [ tc-tsa ] [ reco-
14               tc-tsa ] [ pg-bw ] [ tc-bw ] [ reco-tc-bw ] [ prio-tc ] [ reco-
15               prio-tc ]
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17       dcb ets set dev DEV [ willing { on | off } ] [ { tc-tsa | reco-tc-tsa }
18               TSA-MAP ] [ { pg-bw | tc-bw | reco-tc-bw } BW-MAP ] [ { prio-tc
19               | reco-prio-tc } PRIO-MAP ]
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21       TSA-MAP := [ TSA-MAP ] TSA-MAPPING
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23       TSA-MAPPING := { TC | all }:{ strict | cbs | ets | vendor }
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25       BW-MAP := [ BW-MAP ] BW-MAPPING
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27       BW-MAPPING := { TC | all }:INTEGER
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29       PRIO-MAP := [ PRIO-MAP ] PRIO-MAPPING
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31       PRIO-MAPPING := { PRIO | all }:TC
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33       TC := { 0 .. 7 }
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35       PRIO := { 0 .. 7 }
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DESCRIPTION

39       dcb ets is used to configure Enhanced Transmission Selection attributes
40       through Linux DCB (Data Center Bridging) interface. ETS permits config‐
41       uration of mapping of priorities to traffic classes, traffic selection
42       algorithm to use per traffic class, bandwidth allocation, etc.
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44       Two DCB TLVs are related to the ETS feature: a configuration and recom‐
45       mendation values. Recommendation values are named with a prefix reco-,
46       while the configuration ones have plain names.
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PARAMETERS

50       For read-write parameters, the following describes only the write di‐
51       rection, i.e. as used with the set command. For the show command, the
52       parameter name is to be used as a simple keyword without further argu‐
53       ments. This instructs the tool to show the value of a given parameter.
54       When no parameters are given, the tool shows the complete ETS configu‐
55       ration.
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58       ets-cap
59              A read-only property that shows the number of supported ETS
60              traffic classes.
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63       cbs    A read-only property that is enabled if the driver and the hard‐
64              ware support the CBS Transmission Selection Algorithm.
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67       willing { on | off }
68              Whether local host should accept configuration from peer TLVs.
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71       prio-tc PRIO-MAP
72       reco-prio-tc PRIO-MAP
73              PRIO-MAP uses the array parameter syntax, see dcb(8) for de‐
74              tails. Keys are priorities, values are traffic classes. For each
75              priority sets a TC where traffic with that priority is directed
76              to.
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79       tc-tsa TSA-MAP
80       reco-tc-tsa TSA-MAP
81              TSA-MAP uses the array parameter syntax, see dcb(8) for details.
82              Keys are TCs, values are Transmission Selection Algorithm (TSA)
83              keywords described below. For each TC sets an algorithm used for
84              deciding how traffic queued up at this TC is scheduled for
85              transmission. Supported TSAs are:
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87              strict - for strict priority, where traffic in higher-numbered
88              TCs always takes precedence over traffic in lower-numbered TCs.
89              ets - for Enhanced Traffic Selection, where available bandwidth
90              is distributed among the ETS-enabled TCs according to the
91              weights set by tc-bw and reco-tc-bw, respectively.
92              cbs - for Credit Based Shaper, where traffic is scheduled in a
93              strict manner up to the limit set by a shaper.
94              vendor - for vendor-specific traffic selection algorithm.
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97       tc-bw BW-MAP
98       reco-tc-bw BW-MAP
99              BW-MAP uses the array parameter syntax, see dcb(8) for details.
100              Keys are TCs, values are integers representing percent of avail‐
101              able bandwidth given to the traffic class in question. The value
102              should be 0 for TCs whose TSA is not ets, and the sum of all
103              values shall be 100. As an exception to the standard wording, a
104              configuration with no ets TCs is permitted to sum up to 0 in‐
105              stead.
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108       pg-bw BW-MAP
109              The precise meaning of pg-bw is not standardized, but the as‐
110              sumption seems to be that the same scheduling process as on the
111              transmit side is applicable on receive side as well, and config‐
112              ures receive bandwidth allocation for ets ingress traffic
113              classes (priority groups).
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EXAMPLE & USAGE

117       Configure ETS priomap in a one-to-one fashion:
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120       # dcb ets set dev eth0 prio-tc 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
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122       Set TSA and transmit bandwidth configuration:
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125       # dcb ets set dev eth0 tc-tsa all:strict 0:ets 1:ets 2:ets \
126                              tc-bw all:0 0:33 1:33 2:34
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128       Show what was set:
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130
131       # dcb ets show dev eth0 prio-tc tc-tsa tc-bw
132       prio-tc 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
133       tc-tsa 0:ets 1:ets 2:ets 3:strict 4:strict 5:strict 6:strict 7:strict
134       tc-bw 0:33 1:33 2:34 3:0 4:0 5:0 6:0 7:0
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EXIT STATUS

138       Exit status is 0 if command was successful or a positive integer upon
139       failure.
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REPORTING BUGS

147       Report any bugs to the Network Developers mailing list <net‐
148       dev@vger.kernel.org> where the development and maintenance is primarily
149       done.  You do not have to be subscribed to the list to send a message
150       there.
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AUTHOR

154       Petr Machata <me@pmachata.org>
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158iproute2                        19 October 2020                     DCB-ETS(8)