+.IP "\fBsnoop \fIswitch\fR"
+Connects to \fIswitch\fR and prints to the console all OpenFlow
+messages received. Unlike other \fBovs\-ofctl\fR commands, if
+\fIswitch\fR is the name of a bridge, then the \fBsnoop\fR command
+connects to a Unix domain socket named
+\fB@RUNDIR@/\fIbridge\fB.snoop\fR. \fBovs\-vswitchd\fR listens on
+such a socket for each bridge and sends to it all of the OpenFlow
+messages sent to or received from its configured OpenFlow controller.
+Thus, this command can be used to view OpenFlow protocol activity
+between a switch and its controller.
+.IP
+When a switch has more than one controller configured, only the
+traffic to and from a single controller is output. If none of the
+controllers is configured as a master or a slave (using a Nicira
+extension to OpenFlow), then a controller is chosen arbitrarily among
+them. If there is a master controller, it is chosen; otherwise, if
+there are any controllers that are not masters or slaves, one is
+chosen arbitrarily; otherwise, a slave controller is chosen
+arbitrarily. This choice is made once at connection time and does not
+change as controllers reconfigure their roles.
+.IP
+If a switch has no controller configured, or if
+the configured controller is disconnected, no traffic is sent, so
+monitoring will not show any traffic.
+.
+.IQ "\fBmonitor \fIswitch\fR [\fImiss-len\fR]"