--- a/examples/aodv-with-interface-down.cc	Mon Aug 17 13:19:23 2009 +0400
+++ b/examples/aodv-with-interface-down.cc	Mon Aug 17 15:37:17 2009 +0400
@@ -94,7 +94,7 @@
 
 //-----------------------------------------------------------------------------
 AodvExample::AodvExample () :
-  size (4),
+  size (8),
   step (120),
   totalTime (10),
   pcap (true)
@@ -206,8 +206,8 @@
   p.Start (Seconds (0));
   p.Stop (Seconds (totalTime));
 
-  Ptr<Node> node = nodes.Get (size/2);
+  Ptr<Node> node = nodes.Get (2);
   Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();
-  Simulator::Schedule (Seconds (1), &Ipv4::SetDown, ipv4, 1);
+  Simulator::Schedule (Seconds (3), &Ipv4::SetDown, ipv4, 1);
 }
 

--- a/src/routing/aodv/aodv-neighbor.cc	Mon Aug 17 13:19:23 2009 +0400
+++ b/src/routing/aodv/aodv-neighbor.cc	Mon Aug 17 15:37:17 2009 +0400
@@ -66,16 +66,16 @@
 void
 Neighbors::Update (Ipv4Address addr, Time expire )
 {
-  Purge ();
   for (std::vector<Neighbor>::iterator i = m_nb.begin (); i != m_nb.end (); ++i)
     if (i->m_neighborAddress == addr)
       {
-        i->m_expireTime = expire + Simulator::Now ();
+        i->m_expireTime =  std::max(expire + Simulator::Now (), i->m_expireTime);
         return;
       }
   struct Neighbor neighbor =
   { addr, expire + Simulator::Now () };
   m_nb.push_back (neighbor);
+  Purge ();
 }
 
 void

--- a/src/routing/aodv/aodv-packet.cc	Mon Aug 17 13:19:23 2009 +0400
+++ b/src/routing/aodv/aodv-packet.cc	Mon Aug 17 15:37:17 2009 +0400
@@ -702,7 +702,7 @@
 RerrHeader::AddUnDestination (Ipv4Address dst, uint32_t seqNo )
 {
   if (m_unreachableDstSeqNo.find (dst) != m_unreachableDstSeqNo.end ())
-    return false;
+    return true;
 
   NS_ASSERT (GetDestCount() < 255); // can't support more than 255 destinations in single RERR
   m_unreachableDstSeqNo.insert (std::make_pair (dst, seqNo));

--- a/src/routing/aodv/aodv-routing-protocol.cc	Mon Aug 17 13:19:23 2009 +0400
+++ b/src/routing/aodv/aodv-routing-protocol.cc	Mon Aug 17 15:37:17 2009 +0400
@@ -345,7 +345,7 @@
   RoutingTableEntry toDst;
   if (m_routingTable.LookupRoute (dst, toDst))
     {
-      if (toDst.GetFlag () == INVALID && EnableLocalRepair && !lrtimer.IsRunning())
+      if (toDst.GetFlag () == REPAIRABLE && EnableLocalRepair && !lrtimer.IsRunning())
         {
           if (toDst.GetHop () > MaxRepairTtl)
             return false;
@@ -392,8 +392,17 @@
           ucb (route, p, header);
           return true;
         }
+      else
+        {
+          if (toDst.GetValidSeqNo ())
+            {
+              SendRerrWhenNoRouteToForward (dst, toDst.GetSeqNo (), origin);
+              return false;
+            }
+        }
     }
-  NS_LOG_LOGIC("route not found to "<< dst);
+  NS_LOG_LOGIC("route not found to "<< dst << ". Send RERR message.");
+  SendRerrWhenNoRouteToForward (dst, 0, origin);
   return false;
 }
 
@@ -410,7 +419,7 @@
   if (EnableHello)
     {
       htimer.SetFunction (&RoutingProtocol::HelloTimerExpire, this);
-      htimer.Schedule(MilliSeconds(UniformVariable().GetValue (0.0, 10.0)));
+      htimer.Schedule(MilliSeconds(UniformVariable().GetValue (0.0, 100.0)));
     }
 
   m_ipv4 = ipv4;
@@ -1249,7 +1258,7 @@
   SendHello ();
   // TODO select random time for the next hello
   htimer.Cancel ();
-  Time t = Scalar(0.001)*MilliSeconds(UniformVariable().GetValue (0.0, 100.0));
+  Time t = Scalar(0.01)*MilliSeconds(UniformVariable().GetValue (0.0, 100.0));
   NS_LOG_LOGIC ("delay = " << t.GetMicroSeconds ());
   htimer.Schedule (HelloInterval - t);
 }
@@ -1365,6 +1374,7 @@
     {
       if (!rerrHeader.AddUnDestination (i->first, i->second))
         {
+          NS_LOG_LOGIC ("Send RERR message with maximum size.");
           TypeHeader typeHeader (AODVTYPE_RERR);
           Ptr<Packet> packet = Create<Packet> ();
           packet->AddHeader (rerrHeader);
@@ -1397,6 +1407,43 @@
 }
 
 void
+RoutingProtocol::SendRerrWhenNoRouteToForward (Ipv4Address dst, uint32_t dstSeqNo, Ipv4Address origin)
+{
+  NS_LOG_FUNCTION (this);
+  RerrHeader rerrHeader;
+  rerrHeader.AddUnDestination(dst, dstSeqNo);
+  RoutingTableEntry toOrigin;
+  Ptr<Packet> packet = Create<Packet> ();
+  packet->AddHeader (rerrHeader);
+  packet->AddHeader (TypeHeader (AODVTYPE_RERR));
+  if (m_routingTable.LookupRoute(origin, toOrigin))
+    {
+      if (toOrigin.GetFlag () == VALID)
+        {
+          Ptr<Socket> socket = FindSocketWithInterfaceAddress (toOrigin.GetInterface ());
+          NS_ASSERT (socket);
+          NS_LOG_LOGIC ("unicast RERR to the source of the data transmission");
+          SendPacketViaRawSocket (/*packet*/packet, /*pair<Ptr<Socket> , Ipv4InterfaceAddress>*/ std::make_pair(socket, toOrigin.GetInterface ()),
+                                    /*dst*/toOrigin.GetNextHop (), /*TTL*/ 1, /*id*/0);
+        }
+
+    }
+  else
+    {
+      for (std::map< Ptr<Socket>, Ipv4InterfaceAddress >::const_iterator i = m_socketAddresses.begin (); i != m_socketAddresses.end (); ++i)
+        {
+          Ptr<Socket> socket = i->first;
+          Ipv4InterfaceAddress iface = i->second;
+          NS_ASSERT (socket);
+          NS_LOG_LOGIC ("broadcast RERR meassage from interface " << iface.GetLocal());
+          SendPacketViaRawSocket (/*packet*/packet, /*pair<Ptr<Socket> , Ipv4InterfaceAddress>*/ std::make_pair(socket, iface),
+                                  /*dst*/iface.GetBroadcast (), /*TTL*/1, /*id*/0);
+        }
+    }
+}
+
+
+void
 RoutingProtocol::SendRerr (Ipv4Address dst, bool noDelete)
 {
   RerrHeader rerrHeader;
@@ -1459,7 +1506,7 @@
       Ptr<Socket> socket = FindSocketWithInterfaceAddress (*i);
       NS_ASSERT (socket);
       NS_LOG_LOGIC ("broadcast RERR meassage from interface " << i->GetLocal());
-      SendPacketViaRawSocket (/*packet*/packet, /*pair<Ptr<Socket> , Ipv4InterfaceAddress>*/ std::make_pair(socket, toPrecursor.GetInterface ()),
+      SendPacketViaRawSocket (/*packet*/packet, /*pair<Ptr<Socket> , Ipv4InterfaceAddress>*/ std::make_pair(socket, *i),
                                /*dst*/m_socketAddresses[socket].GetBroadcast (), /*TTL*/ 1, /*id*/0);
     }
 

--- a/src/routing/aodv/aodv-routing-protocol.h	Mon Aug 17 13:19:23 2009 +0400
+++ b/src/routing/aodv/aodv-routing-protocol.h	Mon Aug 17 15:37:17 2009 +0400
@@ -235,6 +235,13 @@
   /// Forward RERR
   void SendRerrMessage(Ptr<Packet> packet,  std::vector<Ipv4Address> precursors);
   /**
+   * Send RERR message when no route to forward input packet. Unicast if there is reverse route to originating node, broadcast otherwise.
+   * \param dst - destination node IP address
+   * \param dstSeqNo - destination node sequence number
+   * \param origin - originating node IP address
+   */
+  void SendRerrWhenNoRouteToForward (Ipv4Address dst, uint32_t dstSeqNo, Ipv4Address origin);
+  /**
   * Add UDP, IP headers to packet and send it via raw socket
   */
   void SendPacketViaRawSocket (Ptr<Packet> packet, std::pair<Ptr<Socket> , Ipv4InterfaceAddress> socketAddress, Ipv4Address dst, uint16_t ttl, uint16_t id);