lldptool
Section: Linux (8)
Updated: August 2012
Page Index
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