.TH lldptool 8 "February 2013" "open-lldp" "Linux"
.SH NAME
evb22 \- Show / manipulate EVB IEEE 802.1 Ratified Standard TLV configuration
.SH SYNOPSIS
.B lldptool -t -i ethx -g ncb -V evb
.sp
.B lldptool -t -i ethx -g ncb -V evb -c
.sp
.B lldptool -t -i ethx -g ncb -V evb -c enabletx
.sp
.B lldptool -T -i ethx -g ncb -V evb -c enabletx=[yes|no]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c evbmode
.sp
.B lldptool -T -i ethx -g ncb -V evb -c evbmode=[bridge|station]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c evbrrreq
.sp
.B lldptool -T -i ethx -g ncb -V evb -c evbrrreq=[yes|no]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c evbrrcap
.sp
.B lldptool -T -i ethx -g ncb -V evb -c evbrrcap=[yes|no]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c evbgpid
.sp
.B lldptool -T -i ethx -g ncb -V evb -c evbgpid=[yes|no]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c ecpretries
.sp
.B lldptool -T -i ethx -g ncb -V evb -c ecpretries=[0..7]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c ecprte
.sp
.B lldptool -T -i ethx -g ncb -V evb -c ecprte=[0..31]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c vdprwd
.sp
.B lldptool -T -i ethx -g ncb -V evb -c vdprwd=[0..31]
.sp
.B lldptool -t -i ethx -g ncb -V evb -c vdprka
.sp
.B lldptool -T -i ethx -g ncb -V evb -c vdprka=[0..31]
.SH DESCRIPTION
The Edge Virtual Bridge (EVB) TLV is a TLV to
announce the station and bridge's edge virtual
bridging (EVB) capabilities and 
may request the bridge port to be
set into reflective relay (hairpin) mode.
If both sides agree on the modes and time out values, 
the edge control protocol (ECP) will be used
to exchange VSI discovery protocol (VDP) data
using ECP frames between the host interface
and the adjacent switch port facing the host
interface.

This man pages describes the IEEE 802.1 Qbg ratified standard
dated from July 5th, 2012.
The arguments and parameters differ from the 
IEEE 802.1 Qbg draft 0.2, which is also implemented.
The EVB protocol version to be used
depends on the organizational unique identifier
(OUI) of the EVB TLV in the LLDP
data stream.
A OUI value of 0x001b3f stands for the IEEE 802.1 Qbg draft 0.2,
a OUI value of 0x0080c2 stands for the IEEE 802.1 Qbg ratified standard.
The version of the ECP and VDP protocols are
determined by the
ethernet type field in the ethernet header.
The ethernet type value for IEEE 802.1 Qbg draft 0.2
is 0x88b7, the value for IEEE 802.1 Qbg ratified standard
is 0x8890.
Note that the EVB protocol is exchanged between
nearest customer bridges only, employing the
reserved multicast MAC address 01:80:c2:00:00:00
as destination MAC address.
.BR lldpad (8)
supports both versions, the switch port configuration
determines which version will be used.
The switch port configuration should select only one
protocol version, never both.
.sp 1 
The command line options and arguments are explained in the 
.BR lldptool (8)
man pages. 
Only the EVB, ECP and VDP protocol specific parameters are 
detailed in this manual page.
.SH ARGUMENTS
The invocation without command line option '-c' and
argument displays the
complete EVB, ECP and VDP protocol settings
in a pretty print out.
See below for a detailed description 
on how to interpret the output.
.TP
\fB\-c\fP \fItext\fP
Use of the command line option '-c' without
any argument displays all known parameters
in the format of
.IR  key = value ,
which is suitable
for post processing.
Use command line option '-c' and one of the
following arguments to display and
set individual parameters.
.I Text
can be one of the following values:
.TP
.B enabletx
Enables or disables the EVB TLV to be transmitted.
When set to disabled no EVB TLV will be included
in the LLDP data stream.
Furthermore the output of the complete EVB settings without
option '-c' will be empty.
.TP
.B evbmode
Display the current role or sets the role the to given value.
Supported values are either 
"station"
or "bridge".
.TP
.B evbrrreq
Shows the current reflective relay (hairpin) request mode or
sets the reflective relay (hairpin) request mode.
If the value is "yes", the station requests the
interface facing switch port to be set in
reflective relay (hairpin) mode.
This field is only valid for stations, 
the output of evbmode equals "station".
.TP
.B evbrrcap
Shows the current reflective relay (hairpin) capabilities or
sets the reflective relay (hairpin) capabilities.
If the value is "yes",
the switch port will be set in
reflective relay (hairpin) mode.
This field is only valid for switches,
the output of evbmode equals "bridge".
.TP
.B gpid
Shows the current station or switch support for grouping
or turns on/off the station or switch support for grouping.
If set to true, the station or switch wants to 
use group identifiers in VDP protocols.
.TP
.B ecpretries
Shows or sets the maximum number of retries for
ECP frames to be retransmitted. 
A retransmit occurs when no ECP acknowledgement
message has been received during a given time period.
.TP
.B ecprte
Shows or sets the local run time exponent (RTE).
The RTE will be used as the
base for the timing of the ECP protocol time outs and
retransmits.
The wait time is calculated as 10*2\u\fIecprte\fP\d micro seconds.
.TP
.B vdprwd
Shows or sets the number of resource wait delay value.
This value is calculated as 10*2\u\fIvdprwd\fP\d micro seconds
and determines the
maximum  wait time for VDP protocol acknowledgements.
.TP
.B vdprka
Shows or sets the number of re-init keep alive value.
This value is calculated as 10*2\u\fIvdprka\fP\d micro seconds
and determines the wait time for VDP protocol 
to send a keep alive message.
.SH Theory of Operation
The EVB TLV is used to announce and exchange supported parameters between
the station and an adjacent switch.
If
.I reflectiverelay
is active, the switch sends back
ethernet frames on the very same port it received the frame on.
This is an extension to the current bridging standard and
allows communication between virtual machines on the
same host through the switch port.
.SH EXAMPLE & USAGE
.TP
Display locally configured values for \fIeth0\fR
.B lldptool -t -g ncb -i eth0 -V evb
.DS
.nf
EVB Configuration TLV
	bridge:(00)
	station:rrreq,rrstat(0x5)
	retries:7 rte:31
	mode:station r/l:0 rwd:31
	r/l:0 rka:8
.fi
.DE
.P
This output is displayed when enabletx has been enabled.
The first line shows the currently known status
of the bridge.
The second line shows the currently known status
of the station.
The status is displayed verbose appended by the
hexadecimal value in parenthesis.
The verbose output uses the bit naming convention
used in the standard document.
The third line displays the values for the
ECP protocol number of retransmits (retries)
and the retransmit timeout exponent.
The forth line shows the current mode of
operation, either bridge or station, 
the resource wait delay value (rwd) and
an indication if the local (0) or remote (1)
rwd value is used.
The fifth line displays the value of the
re-init keep alive counter (rka) and 
an indication if the local (0) or remote (1)
rka value is used.
.TP
Display the currently requested forwarding mode for \fIeth0\fR
.B lldptool -t -g ncb -i eth0 -V evb -c evbrrreq
.TP
Display the locally configured value for RTE
.B lldptool -t -g ncb -i eth0 -V evb -c evbrte
.TP
Set the value for RTE to its maximum value
.B lldptool -T -g ncb -i eth0 -V evb -c rte=7
.TP
Set the value for enabletx to yes
.B lldptool -T -g ncb -i eth0 -V evb -c enabletx=yes
.SH NOTES
Currently the code in lldpad reflects 
IEEE 802.1 Qbg draft 0.2 of the upcoming standard.
Wireshark support for IEEE 802.1 Qbg
ratified standard TLVs is currently missing.
Support for the IEEE 802.1 Qbg ratified standard protocols ECP and VDP
is currently under development and not fully functional.
.SH SEE ALSO
.BR lldptool-vdp (8),
.BR lldptool (8),
.BR lldpad (8)
.br
IEEE 802.1Qbg (http://www.ieee802.org/1/pages/802.1bg.html)
.SH AUTHOR
Thomas Richter
