--- /home/wangke/Desktop/ns-allinone-3.12 (2)/ns-3.12/src/internet/model/ipv4-l3-protocol1.cc	2011-08-28 04:36:05.000000000 +0800
+++ /home/wangke/Desktop/ns-allinone-3.12 (2)/ns-3.12/src/internet/model/ipv4-l3-protocol.cc	2011-11-23 08:35:45.683208047 +0800
@@ -40,7 +40,8 @@
 #include "icmpv4-l4-protocol.h"
 #include "ipv4-interface.h"
 #include "ipv4-raw-socket-impl.h"
-
+//wk test case 
+#include "ns3/ipv4-packet-info-tag.h" 
 NS_LOG_COMPONENT_DEFINE ("Ipv4L3Protocol");
 
 namespace ns3 {
@@ -439,10 +440,18 @@
 
   NS_LOG_LOGIC ("Packet from " << from << " received on node " << 
                 m_node->GetId ());
+//wk test case 
+  Ipv4PacketInfoTag infoTag; 
+  if (p->PeekPacketTag(infoTag )) 
+     { Ipv4Address sender = infoTag.GetAddress(); 
+      sender.Print(std::cout); 
+     } 
+
 
   uint32_t interface = 0;
   Ptr<Packet> packet = p->Copy ();
 
+  
   Ptr<Ipv4Interface> ipv4Interface;
   for (Ipv4InterfaceList::const_iterator i = m_interfaces.begin (); 
        i != m_interfaces.end (); 
@@ -546,6 +555,15 @@
                       Ptr<Ipv4Route> route)
 {
   NS_LOG_FUNCTION (this << packet << source << destination << uint32_t (protocol) << route);
+//wk test case 
+  Ipv4PacketInfoTag infoTag; 
+  packet->RemovePacketTag(infoTag); 
+  infoTag.SetAddress(GetAddress (1, 0).GetLocal ()); 
+  packet->AddPacketTag(infoTag); 
+ // Ipv4Address sender = infoTag.GetAddress(); 
+ // sender.Print(std::cout); 
+
+
 
   Ipv4Header ipHeader;
   bool mayFragment = true;