.IP "\fBpssl:\fR[\fIport\fR][\fB:\fIip\fR]"
.IQ "\fBptcp:\fR[\fIport\fR][\fB:\fIip\fR]"
Listens for OpenFlow connections on \fIport\fR.  By
default, connections are not bound to a particular local IP address, but
\fIip\fR may be specified to listen only for connections to the given
\fIip\fR.  For \fBpssl\fR, the \fB\-\-private\-key\fR,
\fB\-\-certificate\fR, and \fB\-\-ca\-cert\fR options are mandatory.
.IP
If \fIport\fR is not specified, it currently defaults to 6633.  In the
future, the default will change to 6653, which is the IANA-defined
value.
.
.IP "\fBpunix:\fIfile\fR"
Listens for OpenFlow connections on the Unix domain server socket
named \fIfile\fR.