diff -up dhcp-4.2.0/client/dhc6.c.retransmission dhcp-4.2.0/client/dhc6.c
--- dhcp-4.2.0/client/dhc6.c.retransmission	2010-07-21 16:18:51.000000000 +0200
+++ dhcp-4.2.0/client/dhc6.c	2010-07-21 16:19:52.000000000 +0200
@@ -357,7 +357,7 @@ dhc6_retrans_init(struct client_state *c
 static void
 dhc6_retrans_advance(struct client_state *client)
 {
-	struct timeval elapsed;
+	struct timeval elapsed, elapsed_after_RT;
 
 	/* elapsed = cur - start */
 	elapsed.tv_sec = cur_tv.tv_sec - client->start_time.tv_sec;
@@ -374,6 +374,8 @@ dhc6_retrans_advance(struct client_state
 		elapsed.tv_sec += 1;
 		elapsed.tv_usec -= 1000000;
 	}
+	elapsed_after_RT.tv_sec = elapsed.tv_sec;
+	elapsed_after_RT.tv_usec = elapsed.tv_usec;
 
 	/*
 	 * RT for each subsequent message transmission is based on the previous
@@ -411,13 +413,10 @@ dhc6_retrans_advance(struct client_state
 		elapsed.tv_usec -= 1000000;
 	}
 	if (elapsed.tv_sec >= client->MRD) {
-		/*
-		 * wake at RT + cur = start + MRD
-		 */
-		client->RT = client->MRD +
-			(client->start_time.tv_sec - cur_tv.tv_sec);
-		client->RT = client->RT * 100 +
-			(client->start_time.tv_usec - cur_tv.tv_usec) / 10000;
+		client->RT = client->MRD - elapsed_after_RT.tv_sec;
+		client->RT = client->RT * 100 - elapsed_after_RT.tv_usec / 10000;
+		if (client->RT < 0)
+			client->RT = 0;
 	}
 	client->txcount++;
 }
@@ -1505,7 +1504,7 @@ do_init6(void *input)
 		elapsed.tv_usec += 1000000;
 	}
 	/* Check if finished (-1 argument). */
-	if ((client->MRD != 0) && (elapsed.tv_sec > client->MRD)) {
+	if ((client->MRD != 0) && (elapsed.tv_sec >= client->MRD)) {
 		log_info("Max retransmission duration exceeded.");
 		client->state = S_STOPPED;
 		if (client->active_lease != NULL) {
@@ -1925,7 +1924,7 @@ do_info_request6(void *input)
 		elapsed.tv_usec += 1000000;
 	}
 	/* Check if finished (-1 argument). */
-	if ((client->MRD != 0) && (elapsed.tv_sec > client->MRD)) {
+	if ((client->MRD != 0) && (elapsed.tv_sec >= client->MRD)) {
 		log_info("Max retransmission duration exceeded.");
 		exit(2);
 	}
@@ -2046,7 +2045,7 @@ do_confirm6(void *input)
 		elapsed.tv_sec -= 1;
 		elapsed.tv_usec += 1000000;
 	}
-	if ((client->MRD != 0) && (elapsed.tv_sec > client->MRD)) {
+	if ((client->MRD != 0) && (elapsed.tv_sec >= client->MRD)) {
 		log_info("Max retransmission duration exceeded.");
 		start_bound(client);
 		return;
@@ -3293,7 +3292,7 @@ do_select6(void *input)
 		elapsed.tv_sec -= 1;
 		elapsed.tv_usec += 1000000;
 	}
-	if ((client->MRD != 0) && (elapsed.tv_sec > client->MRD)) {
+	if ((client->MRD != 0) && (elapsed.tv_sec >= client->MRD)) {
 		log_info("Max retransmission duration exceeded.");
 		abort = ISC_TRUE;
 	}