.TH ovs\-test 1 "October 2011" "Open vSwitch" "Open vSwitch Manual"
.
.SH NAME
\fBovs\-test\fR \- check Linux drivers for performance and vlan problems
.
.SH SYNOPSIS
\fBovs\-test\fR \fB\-s\fR \fIport\fR
.PP
\fBovs\-test\fR \fB\-c\fR \fIserver1\fR
\fIserver2\fR [\fB\-b\fR \fIbandwidth\fR]
.so lib/common-syn.man
.
.SH DESCRIPTION
The \fBovs\-test\fR program may be used to check for problems sending
802.1Q traffic that Open vSwitch may uncover. These problems can
occur when Open vSwitch is used to send 802.1Q traffic through physical
interfaces running certain drivers of certain Linux kernel versions. To run a
test, configure Open vSwitch to tag traffic originating from \fIserver1\fR and
forward it to the \fIserver2\fR. On both servers run \fBovs\-test\fR
in server mode. Then, on any other host, run the \fBovs\-test\fR in client
mode. The client will connect to both \fBovs\-test\fR servers and schedule
tests between them. \fBovs\-test\fR will perform UDP and TCP tests.
.PP
UDP tests can report packet loss and achieved bandwidth, because UDP flow
control is done inside \fBovs\-test\fR. It is also possible to specify target
bandwidth for UDP. By default it is 1Mbit/s.
.PP
TCP tests report only achieved bandwidth, because kernel TCP stack
takes care of flow control and packet loss. TCP tests are essential to detect
potential TSO related VLAN issues.
.PP
To determine whether Open vSwitch is encountering any 802.1Q related problems,
the user must compare packet loss and achieved bandwidth in a setup where
traffic is being tagged against one where it is not. If in the tagged setup
both servers are unable to communicate or the achieved bandwidth is lower,
then, most likely, Open vSwitch has encountered a pre-existing kernel or
driver bug.
.PP
Some examples of the types of problems that may be encountered are:
.so utilities/ovs-vlan-bugs.man
.
.SS "Client Mode"
An \fBovs\-test\fR client will connect to two \fBovs\-test\fR servers and
will ask them to exchange traffic.
.
.SS "Server Mode"
To conduct tests, two \fBovs\-test\fR servers must be running on two different
hosts where client can connect. The actual test traffic is exchanged only
between both \fBovs\-test\fR server test IP addresses. It is recommended that
both servers have their test IP addresses in the same subnet, otherwise one
will need to change routing so that the test traffic actually goes through the
interface that he originally intended to test.
.
.SH OPTIONS
.
.TP
\fB\-s\fR, \fB\-\-server\fR \fIport\fR
Run in server mode and wait for a client to establish XML RPC Control
Connection on TCP \fIport\fR. It is recommended to have ethtool installed on
the server so that it could retrieve information about NIC driver.
.TP
\fB\-c\fR, \fB\-\-client\fR \fIserver1\fR \fIserver2\fR
Run in client mode and schedule tests between \fIserver1\fR and \fIserver2\fR,
where each \fIserver\fR must be given in following format -
ControlIP[:ControlPort][,TestIP[:TestPort]]. If TestIP is omitted then
ovs-test server will use the ControlIP for testing purposes. ControlPort is
TCP port where server will listen for incoming XML/RPC control
connections to schedule tests (by default it is 15531). TestPort
is port which will be used by server to listen for test traffic
(by default it is 15532).
.TP
\fB\-b\fR, \fB\-\-bandwidth\fR \fIbandwidth\fR
Target bandwidth for UDP tests. The \fIbandwidth\fR must be given in bits per
second. It is possible to use postfix M or K to alter the target bandwidth
magnitude.
.
.so lib/common.man
.SH EXAMPLES
.PP
Set up a bridge which forwards traffic originating from \fB1.2.3.4\fR out
\fBeth1\fR with VLAN tag 10.
.IP
.B ovs\-vsctl \-\- add\-br vlan\-br \(rs
.IP
.B \-\- add\-port vlan\-br eth1 \(rs
.IP
.B \-\- add\-port vlan\-br vlan\-br\-tag tag=10 \(rs
.IP
.B \-\- set Interface vlan\-br\-tag type=internal
.IP
.B ifconfig vlan\-br\-tag up 1.2.3.4
.
.PP
On two different hosts start \fBovs\-test\fR in server mode and tell them to
listen on port 15531 for incoming client control connections:
.IP
.B 1.2.3.4: ovs\-test \-s 15531
.IP
.B 1.2.3.5: ovs\-test \-s 15531
.
.PP
On any other host start \fBovs\-test\fR in client mode and ask it to connect
to those two servers - one at 1.2.3.4 and another at 1.2.3.5 (by default
client will use TCP port 15531 to establish control channel).
.IP
.B ovs\-test -c 1.2.3.4 1.2.3.5
.
.TP

.SH SEE ALSO
.
.BR ovs\-vswitchd (8),
.BR ovs\-ofctl (8),
.BR ovs\-vsctl (8),
.BR ovs\-vlan\-test (8),
.BR ethtool (8),
.BR uname (1)