diff --git a/src/dhcp6.c b/src/dhcp6.c
index 1428aa6..f708af5 100644
--- a/src/dhcp6.c
+++ b/src/dhcp6.c
@@ -26,7 +26,7 @@ struct iface_param {
 
 static int complete_context6(struct in6_addr *local,  int prefix,
 			     int scope, int if_index, int flags, 
-			     int preferred, int valid, void *vparam);
+			     unsigned int preferred, unsigned int valid, void *vparam);
 
 static int make_duid1(int index, unsigned int type, char *mac, size_t maclen, void *parm); 
 
@@ -182,18 +182,15 @@ void dhcp6_packet(time_t now)
 }
 
 static int complete_context6(struct in6_addr *local,  int prefix,
-			     int scope, int if_index, int flags, int preferred, 
-			     int valid, void *vparam)
+			     int scope, int if_index, int flags, unsigned int preferred, 
+			     unsigned int valid, void *vparam)
 {
   struct dhcp_context *context;
   struct iface_param *param = vparam;
   struct iname *tmp;
  
   (void)scope; /* warning */
-  (void)flags;
-  (void)preferred;
-  (void)valid;
-      
+  
   if (if_index == param->ind &&
       !IN6_IS_ADDR_LOOPBACK(local) &&
       !IN6_IS_ADDR_LINKLOCAL(local) &&
@@ -219,12 +216,32 @@ static int complete_context6(struct in6_addr *local,  int prefix,
 	      is_same_net6(local, &context->start6, prefix) &&
 	      is_same_net6(local, &context->end6, prefix))
 	    {
+
+
 	      /* link it onto the current chain if we've not seen it before */
 	      if (context->current == context)
 		{
-		  context->current = param->current;
-		  param->current = context;
+		  struct dhcp_context *tmp, **up;
+		  
+		  /* use interface values only for contructed contexts */
+		  if (!(context->flags & CONTEXT_CONSTRUCTED))
+		    preferred = valid = 0xffffffff;
+		  else if (flags & IFACE_DEPRECATED)
+		    preferred = 0;
+
+		  if (context->flags & CONTEXT_DEPRECATE)
+		    preferred = 0;
+		  
+		  /* order chain, longest preferred time first */
+		  for (up = &param->current, tmp = param->current; tmp; tmp = tmp->current)
+		    if (tmp->preferred <= preferred)
+		      break;
+		  
+		  context->current = *up;
+		  *up = context;
 		  context->local6 = *local;
+		  context->preferred = preferred;
+		  context->valid = valid;
 		}
 	    }
 	}
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index be062f6..3181db6 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -683,6 +683,7 @@ struct dhcp_context {
   struct in6_addr start6, end6; /* range of available addresses */
   struct in6_addr local6;
   int prefix, if_index;
+  unsigned int valid, preferred;
   time_t ra_time, ra_short_period_start;
   char *template_interface;
 #endif
diff --git a/src/radv.c b/src/radv.c
index c552c52..668d56f 100644
--- a/src/radv.c
+++ b/src/radv.c
@@ -344,6 +344,7 @@ static int add_prefixes(struct in6_addr *local,  int prefix,
 	  int do_prefix = 0;
 	  int do_slaac = 0;
 	  int deprecate  = 0;
+	  int constructed = 0;
 	  unsigned int time = 0xffffffff;
 	  struct dhcp_context *context;
 	  
@@ -383,6 +384,10 @@ static int add_prefixes(struct in6_addr *local,  int prefix,
 
 		if (context->flags & CONTEXT_DEPRECATE)
 		  deprecate = 1;
+		
+		if (context->flags & CONTEXT_CONSTRUCTED)
+		  constructed = 1;
+
 
 		/* collect dhcp-range tags */
 		if (context->netid.next == &context->netid && context->netid.net)
@@ -408,18 +413,19 @@ static int add_prefixes(struct in6_addr *local,  int prefix,
 	      }
 
 	  /* configured time is ceiling */
-	  if (valid > time)
+	  if (!constructed || valid > time)
 	    valid = time;
 	  
-	  if ((flags & IFACE_DEPRECATED) || deprecate)
+	  if (flags & IFACE_DEPRECATED)
 	    preferred = 0;
-	  else 
-	    {
-	      /* configured time is ceiling */
-	      if (preferred > time)
-		preferred = time;
-	    }
 	  
+	  if (deprecate)
+	    time = 0;
+	  
+	  /* configured time is ceiling */
+	  if (!constructed || preferred > time)
+	    preferred = time;
+	    	  
 	  if (preferred > param->pref_time)
 	    {
 	      param->pref_time = preferred;
diff --git a/src/rfc3315.c b/src/rfc3315.c
index 8c3cae0..560fdc1 100644
--- a/src/rfc3315.c
+++ b/src/rfc3315.c
@@ -625,10 +625,16 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 				  hostname = NULL;
 			      }
 			  }
+		       	
+			if (have_config(valid_config, CONFIG_TIME))
+			  lease_time = valid_config->lease_time;
+			else
+			  lease_time = this_context->lease_time;
 			
-			lease_time = have_config(valid_config, CONFIG_TIME) ? valid_config->lease_time : this_context->lease_time;
+			 if (this_context->valid < lease_time)
+			   lease_time = this_context->valid;
 			
-			if (ia_option)
+			 if (ia_option)
 			  {
 			    if (requested_time < 120u )
 			      requested_time = 120u; /* sanity */
@@ -740,7 +746,8 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 			    o1 =  new_opt6(OPTION6_IAADDR);
 			    put_opt6(addrp, sizeof(*addrp));
 			    /* preferred lifetime */
-			    put_opt6_long(this_context && (this_context->flags & CONTEXT_DEPRECATE) ? 0 : lease_time);
+			    put_opt6_long(this_context && (this_context->preferred < lease_time) ? 
+					  this_context->preferred : lease_time);
 			    put_opt6_long(lease_time); /* valid lifetime */
 			    end_opt6(o1);