sflow: Improve documentation phrasing.

[openvswitch] / vswitchd / ovs-vswitchd.conf.5.in

diff --git a/vswitchd/ovs-vswitchd.conf.5.in b/vswitchd/ovs-vswitchd.conf.5.in
index 5449e57c605a76a60f836139f77d29c6a876b99a..bb27b0afcb51261a5b2f214183b3ea8f9d814868 100644 (file)
--- a/vswitchd/ovs-vswitchd.conf.5.in
+++ b/vswitchd/ovs-vswitchd.conf.5.in
@@ -460,7 +460,7 @@ netflow.mybr.host=nflow.example.com:9995
 .fi
 .RE
 .SS "sFlow Monitoring"
-sFlow is a protocol for monitoring switches.  A bridge may be
+sFlow(R) is a protocol for monitoring switches.  A bridge may be
 configured to send sFlow records to sFlow collectors by defining the
 key \fBsflow.\fIbridge\fB.host\fR for each collector in the form
 \fIip\fR[\fB:\fIport\fR].  Records from \fIbridge\fR will be sent to
@@ -470,7 +470,7 @@ used.
 .PP
 By default, 1 out of every 400 packets is sent to the configured sFlow
 collector.  To override this, set \fBsflow.\fIbridge\fB.sampling\fR to
-the number of switched packets out of which 1, on average, will be
+the number of switched packets out of which one, on average, will be
 sent to the sFlow collector, e.g. a value of 1 sends every packet to
 the collector, a value of 2 sends 50% of the packets to the collector,
 and so on.
@@ -482,6 +482,15 @@ sFlow collectors, by default every 30 seconds.  To override this, set
 By default, \fBovs\-vswitchd\fR sends the first 128 bytes of sampled
 packets to sFlow collectors.  To override this, set
 \fBsflow.\fIbridge\fB.header\fR to a size in bytes.
+.PP
+The sFlow module must be able to report an ``agent address'' to sFlow
+collectors, which should be an IP address for the Open vSwitch that is
+persistent and reachable over the network, if possible.  If a
+local IP is configured as \fBbridge.\fIbridge\fB.controller.ip\fR,
+then that IP address is used by default.  To override this default,
+set \fBsflow.\fIbridge\fB.agent\fR to the name of a network device, in
+which case the IP address set on that device is used.  If no IP
+address can be determined either way, sFlow is disabled.
 .SS "Remote Management"
 A \fBovs\-vswitchd\fR instance may be remotely managed by a controller that
 supports the OpenFlow Management Protocol, such as NOX.  This