diff --git a/config.c b/config.c
index 56d1556..86ea354 100644
--- a/config.c
+++ b/config.c
@@ -192,6 +192,7 @@ struct config_item config_tab[] = {
 	PORT_ITEM_INT("freq_est_interval", 1, 0, INT_MAX),
 	GLOB_ITEM_INT("gmCapable", 1, 0, 1),
 	PORT_ITEM_INT("hybrid_e2e", 0, 0, 1),
+	PORT_ITEM_INT("ignore_transport_specific", 0, 0, 1),
 	PORT_ITEM_INT("ingressLatency", 0, INT_MIN, INT_MAX),
 	GLOB_ITEM_INT("initial_delay", 0, 0, INT_MAX),
 	GLOB_ITEM_INT("kernel_leap", 1, 0, 1),
diff --git a/port.c b/port.c
index 6cc5dd0..c69363c 100644
--- a/port.c
+++ b/port.c
@@ -125,6 +125,7 @@ struct port {
 	int                 follow_up_info;
 	int                 freq_est_interval;
 	int                 hybrid_e2e;
+	int                 match_transport_specific;
 	int                 min_neighbor_prop_delay;
 	int                 path_trace_enabled;
 	int                 rx_timestamp_offset;
@@ -641,7 +642,8 @@ static int port_ignore(struct port *p, struct ptp_message *m)
 	if (path_trace_ignore(p, m)) {
 		return 1;
 	}
-	if (msg_transport_specific(m) != p->transportSpecific) {
+	if (p->match_transport_specific &&
+	    msg_transport_specific(m) != p->transportSpecific) {
 		return 1;
 	}
 	if (pid_eq(&m->header.sourcePortIdentity, &p->portIdentity)) {
@@ -1489,6 +1491,7 @@ static int port_initialize(struct port *p)
 	p->syncReceiptTimeout      = config_get_int(cfg, p->name, "syncReceiptTimeout");
 	p->transportSpecific       = config_get_int(cfg, p->name, "transportSpecific");
 	p->transportSpecific     <<= 4;
+	p->match_transport_specific = !config_get_int(cfg, p->name, "ignore_transport_specific");
 	p->logSyncInterval         = config_get_int(cfg, p->name, "logSyncInterval");
 	p->logMinPdelayReqInterval = config_get_int(cfg, p->name, "logMinPdelayReqInterval");
 	p->neighborPropDelayThresh = config_get_int(cfg, p->name, "neighborPropDelayThresh");
diff --git a/ptp4l.8 b/ptp4l.8
index 4cf0b0c..9a7701d 100644
--- a/ptp4l.8
+++ b/ptp4l.8
@@ -176,6 +176,14 @@ The default is 0 or disabled.
 The transport specific field. Must be in the range 0 to 255.
 The default is 0.
 .TP
+.B ignore_transport_specific
+By default, incoming messages are dropped if their transportSpecific
+field does not match the configured value.  However, many of
+transports specified in the 1588 standard mandate ignoring this field.
+Moreover, some equipment is known to set the reserved bits.
+Configuring this option as 1 causes this field to be ignored
+completely on receive.  The default is 0.
+.TP
 .B path_trace_enabled
 Enable the mechanism used to trace the route of the Announce messages.
 The default is 0 (disabled).