diff --git a/clock.c b/clock.c
index bc2c061..e861b9b 100644
--- a/clock.c
+++ b/clock.c
@@ -334,6 +334,11 @@ void clock_path_delay(struct clock *c, struct timespec req, struct timestamp rx,
 	pr_debug("path delay    %10lld", c->path_delay);
 }
 
+int clock_slave_only(struct clock *c)
+{
+	return c->dds.slaveOnly;
+}
+
 void clock_synchronize(struct clock *c,
 		       struct timespec ingress_ts, struct timestamp origin_ts,
 		       Integer64 correction1, Integer64 correction2)
diff --git a/clock.h b/clock.h
index 1342143..92b29a5 100644
--- a/clock.h
+++ b/clock.h
@@ -126,6 +126,13 @@ void clock_path_delay(struct clock *c, struct timespec req, struct timestamp rx,
  */
 int clock_poll(struct clock *c);
 
+/**
+ * Obtain the slave-only flag from a clock's default data set.
+ * @param c  The clock instance.
+ * @return   The value of the clock's slave-only flag.
+ */
+int clock_slave_only(struct clock *c);
+
 /**
  * Provide a data point to synchronize the clock.
  * @param c            The clock instance to synchronize.
diff --git a/linuxptp.c b/linuxptp.c
index ecaa31f..a350261 100644
--- a/linuxptp.c
+++ b/linuxptp.c
@@ -135,6 +135,7 @@ int main(int argc, char *argv[])
 		phc = NULL;
 	}
 
+	ds.slaveOnly = TRUE; // TODO - make this programmable.
 	ds.priority1 = 128;
 	ds.clockQuality.clockClass = 248;
 	ds.clockQuality.clockAccuracy = 0xfe;
diff --git a/makefile b/makefile
index e163f5b..9c29c50 100644
--- a/makefile
+++ b/makefile
@@ -32,7 +32,7 @@ DEPEND	= $(OBJ:.o=.d)
 srcdir	:= $(dir $(lastword $(MAKEFILE_LIST)))
 VPATH	= $(srcdir)
 
-all: $(OBJ)
+all: linuxptp
 
 linuxptp: $(OBJ)
 
diff --git a/port.c b/port.c
index 6aa4d44..c1e2c67 100644
--- a/port.c
+++ b/port.c
@@ -584,7 +584,8 @@ struct foreign_clock *port_compute_best(struct port *p)
 
 void port_dispatch(struct port *p, enum fsm_event event)
 {
-	enum port_state next = ptp_fsm(p->state, event);
+	enum port_state next = clock_slave_only(p->clock) ?
+		ptp_slave_fsm(p->state, event) : ptp_fsm(p->state, event);
 
 	if (PS_INITIALIZING == next) {
 		/*