NTP conflates broadcast and multicast when opening sockets. The broadcast

address does not need to be opened for multicast clients. This has been

reported as NTP community bug 2990 (http://bugs.ntp.org/show_bug.cgi?id=2990)

and this patch may be removed after upgrading to a version of NTP which has

bug 2990 fixed.

--- include/ntpd.h

+++ include/ntpd.h

@@ -480,6 +480,7 @@ extern struct peer *sys_peer;		/* curren

  * Nonspecified system state variables.

  */

 extern int	sys_bclient;		/* we set our time to broadcasts */

+extern int	sys_mclient;		/* we set our time to multicast */

 extern double	sys_bdelay; 		/* broadcast client default delay */

 extern int	sys_authenticate;	/* requre authentication for config */

 extern l_fp	sys_authdelay;		/* authentication delay */

--- ntpd/ntp_io.c

+++ ntpd/ntp_io.c

@@ -2017,9 +2017,6 @@ update_interfaces(

 	 */

 	refresh_all_peerinterfaces();

-	if (broadcast_client_enabled)

-		io_setbclient();

-

 	if (sys_bclient)

 		io_setbclient();

--- ntpd/ntp_proto.c

+++ ntpd/ntp_proto.c

@@ -105,6 +105,7 @@ int leap_sec_in_progress;

  * Nonspecified system state variables

  */

 int	sys_bclient;		/* broadcast client enable */

+int	sys_mclient;		/* multicast client enable */

 double	sys_bdelay;		/* broadcast client default delay */

 int	sys_authenticate;	/* requre authentication for config */

 l_fp	sys_authdelay;		/* authentication delay */

@@ -1083,7 +1084,7 @@ receive(

 			return;

 		}

 #endif /* AUTOKEY */

-		if (sys_bclient == 0) {

+		if (sys_bclient == 0 && sys_mclient == 0) {

 			sys_restricted++;

 			return;			/* not enabled */

 		}

@@ -4209,6 +4210,7 @@ init_proto(void)

 	sys_survivors = 0;

 	sys_manycastserver = 0;

 	sys_bclient = 0;

+	sys_mclient = 0;

 	sys_bdelay = BDELAY_DEFAULT;	/*[Bug 3031] delay cutoff */

 	sys_authenticate = 1;

 	sys_stattime = current_time;

@@ -4356,7 +4358,7 @@ proto_config(

 	case PROTO_MULTICAST_ADD: /* add group address */

 		if (svalue != NULL)

 			io_multicast_add(svalue);

-		sys_bclient = 1;

+		sys_mclient = 1;

 		break;

 	case PROTO_MULTICAST_DEL: /* delete group address */

--- ntpd/ntp_request.c

+++ ntpd/ntp_request.c

@@ -1117,7 +1117,7 @@ sys_info(

 	is->flags = 0;

 	if (sys_authenticate)

 		is->flags |= INFO_FLAG_AUTHENTICATE;

-	if (sys_bclient)

+	if (sys_bclient || sys_mclient)

 		is->flags |= INFO_FLAG_BCLIENT;

 #ifdef REFCLOCK

 	if (cal_enable)