diff --git a/bin/named/client.c b/bin/named/client.c
index 9671907bd6..508d269987 100644
--- a/bin/named/client.c
+++ b/bin/named/client.c
@@ -1656,8 +1656,18 @@ client_request(isc_task_t *task, isc_event_t *event) {
 	/*
 	 * Deal with EDNS.
 	 */
-	opt = dns_message_getopt(client->message);
+	if (ns_g_noedns)
+		opt = NULL;
+	else
+		opt = dns_message_getopt(client->message);
 	if (opt != NULL) {
+		/*
+		 * Are we dropping all EDNS queries?
+		 */
+		if (ns_g_dropedns) {
+			ns_client_next(client, ISC_R_SUCCESS);
+			goto cleanup;
+		}
 		/*
 		 * Set the client's UDP buffer size.
 		 */
diff --git a/bin/named/include/named/globals.h b/bin/named/include/named/globals.h
index 72dd1e8639..8197f55449 100644
--- a/bin/named/include/named/globals.h
+++ b/bin/named/include/named/globals.h
@@ -152,6 +152,8 @@ EXTERN int			ns_g_listen		INIT(3);
 EXTERN isc_time_t		ns_g_boottime;
 EXTERN isc_boolean_t		ns_g_memstatistics	INIT(ISC_FALSE);
 EXTERN isc_boolean_t		ns_g_clienttest		INIT(ISC_FALSE);
+EXTERN isc_boolean_t		ns_g_dropedns		INIT(ISC_FALSE);
+EXTERN isc_boolean_t		ns_g_noedns		INIT(ISC_FALSE);
 EXTERN isc_boolean_t		ns_g_nosoa		INIT(ISC_FALSE);
 EXTERN isc_boolean_t		ns_g_noaa		INIT(ISC_FALSE);
 EXTERN unsigned int		ns_g_delay		INIT(0);
diff --git a/bin/named/main.c b/bin/named/main.c
index eb3b3f4e7f..3c8c08fec2 100644
--- a/bin/named/main.c
+++ b/bin/named/main.c
@@ -525,6 +525,13 @@ parse_command_line(int argc, char *argv[]) {
 				maxudp = 512;
 			else if (!strcmp(isc_commandline_argument, "maxudp1460"))
 				maxudp = 1460;
+			else if (!strcmp(isc_commandline_argument, "dropedns"))
+				ns_g_dropedns = ISC_TRUE;
+			else if (!strcmp(isc_commandline_argument, "noedns"))
+				ns_g_noedns = ISC_TRUE;
+			else if (!strncmp(isc_commandline_argument,
+					  "maxudp=", 7))
+				maxudp = atoi(isc_commandline_argument + 7);
 			else if (!strncmp(isc_commandline_argument,
 					  "delay=", 6))
 				ns_g_delay = atoi(isc_commandline_argument + 6);
diff --git a/bin/tests/system/start.pl b/bin/tests/system/start.pl
index fb243c27d4..12f7c7a854 100644
--- a/bin/tests/system/start.pl
+++ b/bin/tests/system/start.pl
@@ -253,7 +253,7 @@ sub verify_server {
 
 	my $tries = 0;
 	while (1) {
-		my $return = system("$DIG +tcp +noadd +nosea +nostat +noquest +nocomm +nocmd -p 5300 version.bind. chaos txt \@10.53.0.$n > dig.out");
+		my $return = system("$DIG +tcp +noadd +nosea +nostat +noquest +nocomm +nocmd +noedns -p 5300 version.bind. chaos txt \@10.53.0.$n > dig.out");
 		last if ($return == 0);
 		if (++$tries >= 30) {
 			print `grep ";" dig.out > /dev/null`;
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index da9d82608a..a7fc65ed98 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -1765,7 +1765,7 @@ doio_recv(isc__socket_t *sock, isc_socketevent_t *dev) {
 		}
 		/*
 		 * Simulate a firewall blocking UDP responses bigger than
-		 * 512 bytes.
+		 * 'maxudp' bytes.
 		 */
 		if (sock->manager->maxudp != 0 && cc > sock->manager->maxudp)
 			return (DOIO_SOFT);
@@ -1859,7 +1859,12 @@ doio_send(isc__socket_t *sock, isc_socketevent_t *dev) {
 	build_msghdr_send(sock, dev, &msghdr, iov, &write_count);
 
  resend:
-	cc = sendmsg(sock->fd, &msghdr, 0);
+	if (sock->type == isc_sockettype_udp &&
+	    sock->manager->maxudp != 0 &&
+	    write_count > (size_t)sock->manager->maxudp) 
+		cc = write_count;
+	else
+		cc = sendmsg(sock->fd, &msghdr, 0);
 	send_errno = errno;
 
 	/*