lldptool(8) Linux lldptool(8)NAME
ETS-{CFG|REC} - Show / manipulate ETS TLV configuration
SYNOPSIS
lldptool -t -i ethx -V ETS-CFG <-c CONFIG_ARG ...>
CONFIG_ARG := { enableTx | willing | tsa | up2tc | numtcs | tcbw }
lldptool -T -i ethx -V ETS-CFG CONFIG_ARG=value ...
CONFIG_ARG :=
enableTx = {yes|no} |
willing = {yes|no} |
tsa = tc:{ets|strict|vendor},... |
up2tc = priority:tc,... |
tcbw = bw1,bw2,...
lldptool -t -i ethx -V ETS-REC <-c CONFIG_ARG ...>
lldptool -T -i ethx -V ETS-REC CONFIG_ARG=value ...
CONFIG_ARG :=
enableTx = {yes|no} |
tsa = tc:{ets|strict|vendor},... |
up2tc = priority:tc,... |
tcbw = bw1,bw2,...
DESCRIPTION
The Enhanced Transmission Selection (ETS) feature has a recommendation
TLV and a configuration TLV configured with ETS-REC and ETS-CFG respec‐
tively.
ARGUMENTS
enableTx
Enables the ETS TLV to be transmitted
willing
Sets the ETS-CFG willing bit
tsa Transmission selection algorithm, sets a comma seperated list of
traffic classes to the corresponding selection algorithm. Valid
algorithms include "ets", "strict" and "vendor".
up2tc Comma seperated list mapping user priorities to traffic classes.
tcbw Comma separated list of bandwiths for each traffic class the
first value being assigned to traffic class 0 and the second to
traffic class 1 and so on. Undefined bandwidths are presumed to
be 0.
numtcs Sets/Displays the number of ETS supported traffic classes.
Theory of Operations
IEEE 802.1Qaz is enabled by default on hardware that supports this mode
indicated by support for the DCBNL interface. Kernel config option CON‐
FIG_DCB. The ETS-CFG TLV is advertised by default with the attributes
indicated by querying the hardware for its current configuration. A
valid configuration is to map all priorities to a single traffic class
and use the link strict selection algorithm. This is equivalent to
being in a non-DCB enabled mode.
To support legacy CEE DCBX the ETS-CFG and ETS-REC TLVs are disabled if
a CEE TLV is received and there are no valid IEEE 802.1Qaz TLVs
present. At this time the hardware DCBX mode will be set to CEE and
IEEE mode is disabled. This allows switches to be configured and end
nodes will then be configured accordingly without any configuration
required on the end node.
Mapping applications and protocols to traffic classes is required for
ETS to be useful. User space programs can encode the priority of an
application with the SO_PRIORITY option. Low level drivers that support
priority to traffic class mappings may enable this mode by default. For
drivers that do not support this mode manual configuration can support
this mode of operation see tc-mqprio(8) and tc-multiq. Additionally,
tc qdiscs and filters can be used to map protocols to queues see tc(8)
for more details along these lines. Finally, many drivers have support
for specific protocols ie Fiber Channel over Ethernet (FCoE).
EXAMPLE & USAGE
Configure willing bit for interface eth2
lldptool -T -i eth2 -V ETS-CFG willing=yes
Configure traffic classes for ETS and strict priority on eth2
lldptool -T -i eth2 -V ETS-CFG
tsa=0:ets,1:ets,2:ets,3:ets,4:strict,5:strict
Configure 1:1 mapping from priority to traffic classes on eth2
lldptool -T-i eth2 -V ETS-CFG
up2tc=0:0,1:1,2:2,3:3,4:4,5:5,6:6,7:7
Display local configured ETS-CFG parameters for tcbw
lldptool -t -i eth2 -V ETS-CFG -c tcbw
Display last transmitted ETS-CFG TLV
lldptool -t -i eth2 -V ETS-CFG
Configure ETS-CFG and ETS-REC for default DCB on eth2
lldptool -T -i eth2 -V ETS-CFG
tsa=0:ets,1:ets,2:ets,3:ets,4:ets,5:ets,6:ets,7:ets
up2tc=0:0,1:1,2:2,3:3,4:4,5:5,6:6,7:7
tcbw=12,12,12,12,13,13,13,13
lldptool -T-i eth2 -V ETS-REC
tsa=0:ets,1:ets,2:ets,3:ets,4:ets,5:ets,6:ets,7:ets
up2tc=0:0,1:1,2:2,3:3,4:4,5:5,6:6,7:7
tcbw=12,12,12,12,13,13,13,13
SOURCE
o IEEE 802.1Qaz (http://www.ieee802.org/1/pages/dcbridges.html)
NOTES
Support for tc-mqprio was added in 2.6.38 on older kernels other mecha‐
nisms may need to be used to map applications to traffic classes.
SEE ALSOlldptool(8), lldptool-app(8), lldpad(8), tc-mqprio(8),
AUTHOR
John Fastabend
open-lldp February 2010 lldptool(8)
