--- a/src/point-to-point/model/point-to-point-net-device.cc	Fri Mar 18 14:24:12 2016 +0000
+++ b/src/point-to-point/model/point-to-point-net-device.cc	Fri Mar 18 14:35:44 2016 +0000
@@ -251,6 +251,8 @@
   NS_LOG_FUNCTION (this << p);
   NS_LOG_LOGIC ("UID is " << p->GetUid () << ")");
 
+  m_macTxTrace (p);
+  
   //
   // This function is called to start the process of transmitting a packet.
   // We need to tell the channel that we've started wiggling the wire and
@@ -568,8 +570,6 @@
   //
   AddHeader (packet, protocolNumber);
 
-  m_macTxTrace (packet);
-
   //
   // We should enqueue and dequeue the packet to hit the tracing hooks.
   //