lldptool-pfc(8) [centos man page]
lldptool(8) Linux lldptool(8) NAME
PFC - Show / manipulate PFC TLV configuration SYNOPSIS
lldptool -t -i ethx -V PFC [ -c [ enableTx | willing | enabled | delay ] ] lldptool -T -i ethx -V PFC <CONFIG_ARG=value ...> CONFIG_ARG:= enableTx=<yes|no> willing=<yes|no|0|1> enabled=<none|[0..7],[0..7],...> delay=<integer value> DESCRIPTION
The PFC TLV is used to display and set current PFC TLV attributes. ARGUMENTS
enableTx Enable the PFC TLV to be transmitted in the LLDP PDU for the specified interface. willing Display or set the willing attribute. If set to yes and a peer TLV is received then the peer PFC attributes will be used. If set to no then locally configured attributes are used. enabled Display or set the priorities with PFC enabled. The set attribute takes a comma separated list of priorities to enable, or the string none to disable all priorities. delay Display or set the delay attribute used to configure PFC thresholds in hardware buffers. If PFC is enabled and frames continue to be dropped due to full hardware buffers then increasing this value may help. Theory of Operations The PFC TLV uses the Symmetric attribute passing state machine defined in IEEE 802.1Qaz. This means the attributes used will depend on the willing bit. If the willing bit is set to 1 and a peer TLV is received then the peers attributes will be used. If the willing bit is set to 0 the local attributes will be used. When both the peer and local configuration are willing a tie breaking scheme is used. For more detailed coverage see the specification. EXAMPLE &; USAGE Enable PFC for priorities 1, 2, and 4 on eth2 lldptool -T -i eth2 -V PFC enabled=1,2,4 Disable PFC for all priorities on eth2 lldptool -T -i eth2 -V PFC enabled=none Display configuration of PFC enabled priorities for eth2 lldptool -t -i eth2 -V PFC -c enabled Display last transmitted PFC TLV on eth2 lldptool -t -i eth2 -V PFC SOURCE
o IEEE 802.1Qaz (http://www.ieee802.org/1/pages/dcbridges.html) NOTES
SEE ALSO
lldptool(8), lldpad(8) AUTHOR
John Fastabend open-lldp August 2012 lldptool(8)
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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 respectively. 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 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 CONFIG_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 DCBX (CIN or CEE) the ETS-CFG and ETS-REC TLVs are disabled if a legacy DCBX TLV is received and no valid IEEE DCBX TLVs are received. The hardware DCBX mode will also be set to the legacy mode 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. See lldpad(8) for more information about the operation of the DCBX selection mechanism. 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. The net_prio cgroup can be used to assign application traffic to specific priorities. See the kernel documentation and cgdcbxd(8) for net_prio cgroup information. 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 mechanisms may need to be used to map applications to traffic classes. SEE ALSO
lldptool(8), lldptool-app(8), lldpad(8), tc-mqprio(8), AUTHOR
John Fastabend open-lldp February 2010 lldptool(8)