According to the latest SNTPv4 spec in RFC4330, secondary servers

return the address of the synchronization source as reference
identification.  Remove the obsolete special casing specified in RFC2030.
ok henning@

src/usr.sbin/ntpd/client.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: client.c,v 1.79 2008/01/28 11:45:59 mpf Exp $ */
+/*	$OpenBSD: client.c,v 1.80 2008/06/10 03:46:09 naddy Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -263,7 +263,6 @@ client_dispatch(struct ntp_peer *p, u_int8_t settime)
 	p->reply[p->shift].status.rootdelay = sfp_to_d(msg.rootdelay);
 	p->reply[p->shift].status.rootdispersion = sfp_to_d(msg.dispersion);
 	p->reply[p->shift].status.refid = ntohl(msg.refid);
-	p->reply[p->shift].status.refid4 = msg.xmttime.fractionl;
 	p->reply[p->shift].status.reftime = lfp_to_d(msg.reftime);
 	p->reply[p->shift].status.poll = msg.ppoll;
 	p->reply[p->shift].status.stratum = msg.stratum;

src/usr.sbin/ntpd/ntp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.105 2008/06/08 19:14:40 ckuethe Exp $ */
+/*	$OpenBSD: ntp.c,v 1.106 2008/06/10 03:46:09 naddy Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -576,7 +576,6 @@ priv_adjtime(void)
 	conf->status.stratum++;	/* one more than selected peer */
 	update_scale(offset_median);
 
-	conf->status.refid4 = offsets[i]->status.refid4;
 	conf->status.refid = offsets[i]->status.send_refid;
 
 	free(offsets);

src/usr.sbin/ntpd/ntpd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.94 2008/06/09 18:30:48 deraadt Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.95 2008/06/10 03:46:09 naddy Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -97,7 +97,6 @@ struct ntp_status {
 	double		rootdispersion;
 	double		reftime;
 	u_int32_t	refid;
-	u_int32_t	refid4;
 	u_int32_t	send_refid;
 	u_int8_t	synced;
 	u_int8_t	leap;

src/usr.sbin/ntpd/sensors.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: sensors.c,v 1.39 2008/06/09 18:30:48 deraadt Exp $ */
+/*	$OpenBSD: sensors.c,v 1.40 2008/06/10 03:46:09 naddy Exp $ */
 
 /*
  * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
@@ -191,7 +191,6 @@ sensor_query(struct ntp_sensor *s)
 	s->offsets[s->shift].good = 1;
 
 	s->offsets[s->shift].status.refid = s->refid;
-	s->offsets[s->shift].status.refid4 = s->refid;
 	s->offsets[s->shift].status.stratum = 0;	/* increased when sent out */
 	s->offsets[s->shift].status.rootdelay = 0;
 	s->offsets[s->shift].status.rootdispersion = 0;

src/usr.sbin/ntpd/server.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: server.c,v 1.31 2007/01/15 08:19:11 otto Exp $ */
+/*	$OpenBSD: server.c,v 1.32 2008/06/10 03:46:09 naddy Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -162,11 +162,7 @@ server_dispatch(int fd, struct ntpd_conf *lconf)
 	reply.xmttime = d_to_lfp(gettime_corrected());
 	reply.orgtime = query.xmttime;
 	reply.rootdelay = d_to_sfp(lconf->status.rootdelay);
-
-	if (version > 3)
-		reply.refid = lconf->status.refid4;
-	else
-		reply.refid = lconf->status.refid;
+	reply.refid = lconf->status.refid;
 
 	ntp_sendmsg(fd, (struct sockaddr *)&fsa, &reply, size, 0);
 	return (0);