diff --git a/RELNOTES b/RELNOTES
index 59675213..2b8e10bc 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -122,6 +122,12 @@ and for prodding me into improving it.
 - The DHCP Relay Agent Information Option / Link Selection Sub-Option
   is now supported.  (See RFC3527 for details).
 
+- A new DDNS related server option, update-conflict-detection, has been
+  added.  If this option is enabled, dhcpd will perform normal DHCID
+  conflict resolution (the default).  If this option is disabled, it will
+  instead trust the assigned name implicitly (removing any other bindings
+  on that name).  This option has not been made available in dhclient.
+
 			Changes since 3.0.4
 
 - A warning that host statements declared within subnet or shared-network
diff --git a/client/dhclient.c b/client/dhclient.c
index fff2f3e1..53ac8317 100644
--- a/client/dhclient.c
+++ b/client/dhclient.c
@@ -32,7 +32,7 @@
 
 #ifndef lint
 static char ocopyright[] =
-"$Id: dhclient.c,v 1.141 2006/07/09 15:39:48 dhankins Exp $ Copyright (c) 2004-2006 Internet Systems Consortium.  All rights reserved.\n";
+"$Id: dhclient.c,v 1.142 2006/07/19 17:14:55 dhankins Exp $ Copyright (c) 2004-2006 Internet Systems Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -3178,7 +3178,7 @@ isc_result_t client_dns_update (struct client_state *client, int addp, int ttl)
 			rcode = ddns_update_a (&ddns_fwd_name,
 					       client -> active -> address,
 					       &ddns_dhcid, ttl,
-					       1);
+					       1, 1);
 		else
 			rcode = ddns_remove_a (&ddns_fwd_name,
 					       client -> active -> address,
diff --git a/common/dns.c b/common/dns.c
index 97804ec5..44efb7ee 100644
--- a/common/dns.c
+++ b/common/dns.c
@@ -33,7 +33,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: dns.c,v 1.39 2006/06/01 20:23:17 dhankins Exp $ Copyright (c) 2004-2006 Internet Systems Consortium.  All rights reserved.\n";
+"$Id: dns.c,v 1.40 2006/07/19 17:14:55 dhankins Exp $ Copyright (c) 2004-2006 Internet Systems Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -518,10 +518,10 @@ int get_dhcid (struct data_string *id,
 /* Now for the DDNS update code that is shared between client and
    server... */
 
-isc_result_t ddns_update_a (struct data_string *ddns_fwd_name,
-			    struct iaddr ddns_addr,
-			    struct data_string *ddns_dhcid,
-			    unsigned long ttl, int rrsetp)
+isc_result_t
+ddns_update_a(struct data_string *ddns_fwd_name, struct iaddr ddns_addr,
+	      struct data_string *ddns_dhcid, unsigned long ttl,
+	      unsigned rrsetp, unsigned conflict)
 {
 	ns_updque updqueue;
 	ns_updrec *updrec;
@@ -654,23 +654,45 @@ isc_result_t ddns_update_a (struct data_string *ddns_fwd_name,
 		minires_freeupdrec (updrec);
 	}
 
-	/*
-	 * DHCID RR exists, and matches client identity.
+	/* If we're doing conflict resolution, we use a set of prereqs.  If
+	 * not, we delete the DHCID in addition to all A rrsets.
 	 */
-	updrec = minires_mkupdrec (S_PREREQ,
-				   (const char *)ddns_fwd_name -> data,
-				   C_IN, T_DHCID, 0);
-	if (!updrec) {
-		result = ISC_R_NOMEMORY;
-		goto error;
+	if (conflict) {
+		/*
+		 * DHCID RR exists, and matches client identity.
+		 */
+		updrec = minires_mkupdrec (S_PREREQ,
+					   (const char *)ddns_fwd_name -> data,
+					   C_IN, T_DHCID, 0);
+		if (!updrec) {
+			result = ISC_R_NOMEMORY;
+			goto error;
+		}
+	
+		updrec -> r_data = ddns_dhcid -> data;
+		updrec -> r_size = ddns_dhcid -> len;
+		updrec -> r_opcode = YXRRSET;
+
+		ISC_LIST_APPEND (updqueue, updrec, r_link);
+	} else {
+		/*
+		 * Conflict detection override: delete DHCID RRs.
+		 */
+		updrec = minires_mkupdrec(S_UPDATE, ddns_fwd_name->data,
+					  C_IN, T_DHCID, 0);
+
+		if (!updrec) {
+			result = ISC_R_NOMEMORY;
+			goto error;
+		}
+
+		updrec->r_data = NULL;
+		updrec->r_size = 0;
+		updrec->r_opcode = DELETE;
+
+		ISC_LIST_APPEND(updqueue, updrec, r_link);
 	}
 
-	updrec -> r_data = ddns_dhcid -> data;
-	updrec -> r_size = ddns_dhcid -> len;
-	updrec -> r_opcode = YXRRSET;
-
-	ISC_LIST_APPEND (updqueue, updrec, r_link);
-
 
 	/*
 	 * Delete A RRset.
diff --git a/includes/dhcpd.h b/includes/dhcpd.h
index 4735be73..a0cc560b 100644
--- a/includes/dhcpd.h
+++ b/includes/dhcpd.h
@@ -510,6 +510,7 @@ struct lease_state {
 #define SV_DO_FORWARD_UPDATES		45
 #define SV_PING_TIMEOUT			46
 #define SV_RESERVE_INFINITE		47
+#define SV_DDNS_CONFLICT_DETECT		48
 
 #if !defined (DEFAULT_PING_TIMEOUT)
 # define DEFAULT_PING_TIMEOUT 1
@@ -2186,8 +2187,9 @@ void forget_zone (struct dns_zone **);
 void repudiate_zone (struct dns_zone **);
 void cache_found_zone (ns_class, char *, struct in_addr *, int);
 int get_dhcid (struct data_string *, int, const u_int8_t *, unsigned);
-isc_result_t ddns_update_a (struct data_string *, struct iaddr,
-			    struct data_string *, unsigned long, int);
+isc_result_t ddns_update_a(struct data_string *, struct iaddr,
+			   struct data_string *, unsigned long, unsigned,
+			   unsigned);
 isc_result_t ddns_remove_a (struct data_string *,
 			    struct iaddr, struct data_string *);
 #endif /* NSUPDATE */
diff --git a/server/ddns.c b/server/ddns.c
index b2811324..483d9a3f 100644
--- a/server/ddns.c
+++ b/server/ddns.c
@@ -34,7 +34,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: ddns.c,v 1.19 2006/06/01 20:23:17 dhankins Exp $ Copyright (c) 2004-2005 Internet Systems Consortium.  All rights reserved.\n";
+"$Id: ddns.c,v 1.20 2006/07/19 17:14:55 dhankins Exp $ Copyright (c) 2004-2005 Internet Systems Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -548,9 +548,23 @@ int ddns_updates (struct packet *packet,
 	/*
 	 * Perform updates.
 	 */
-	if (ddns_fwd_name.len && ddns_dhcid.len)
+	if (ddns_fwd_name.len && ddns_dhcid.len) {
+		unsigned conflict;
+
+		oc = lookup_option(&server_universe, state->options,
+				   SV_DDNS_CONFLICT_DETECT);
+		if (!oc ||
+		    evaluate_boolean_option_cache(&ignorep, packet, lease,
+						  NULL, packet->options,
+						  state->options,
+						  &lease->scope, oc, MDL))
+			conflict = 1;
+		else
+			conflict = 0;
+
 		rcode1 = ddns_update_a (&ddns_fwd_name, lease -> ip_addr,
-					&ddns_dhcid, ddns_ttl, 0);
+					&ddns_dhcid, ddns_ttl, 0, conflict);
+	}
 	
 	if (rcode1 == ISC_R_SUCCESS) {
 		if (ddns_fwd_name.len && ddns_rev_name.len)
diff --git a/server/dhcpd.conf.5 b/server/dhcpd.conf.5
index 2119a600..820f96bf 100644
--- a/server/dhcpd.conf.5
+++ b/server/dhcpd.conf.5
@@ -28,7 +28,7 @@
 .\" see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 .\" ``http://www.nominum.com''.
 .\"
-.\" $Id: dhcpd.conf.5,v 1.75 2006/07/09 15:01:19 dhankins Exp $
+.\" $Id: dhcpd.conf.5,v 1.76 2006/07/19 17:14:55 dhankins Exp $
 .\"
 .TH dhcpd.conf 5
 .SH NAME
@@ -2400,6 +2400,19 @@ directly to the server and not sent through a relay agent.
 .RE
 .PP
 The
+.I update-conflict-detection
+statement
+.RS 0.25i
+.PP
+.B update-conflict-detection \fIflag\fB;\fR
+.PP
+If the \fIupdate-conflict-detection\fR parameter is true, the server will
+perform standard DHCID multiple-client, one-name conflict detection.  If
+the parameter has been set false, the server will skip this check and
+instead simply tear down any previous bindings to install the new
+binding without question.  The default is true.
+.PP
+The
 .I update-optimization
 statement
 .RS 0.25i
diff --git a/server/stables.c b/server/stables.c
index 7c7df5ca..4bfbaf25 100644
--- a/server/stables.c
+++ b/server/stables.c
@@ -34,7 +34,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: stables.c,v 1.31 2006/07/17 15:16:43 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium.  All rights reserved.\n";
+"$Id: stables.c,v 1.32 2006/07/19 17:14:55 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -233,6 +233,7 @@ static struct option server_options[] = {
 	{ "do-forward-updates", "f",		&server_universe,  45, 1 },
 	{ "ping-timeout", "T",			&server_universe,  46, 1 },
 	{ "infinite-is-reserved", "f",		&server_universe,  47, 1 },
+	{ "update-conflict-detection", "f",	&server_universe,  48, 1 },
 	{ NULL, NULL, NULL, 0, 0 }
 };