diff -cr ORIG/source/ns-3-dce/helper/linux-stack-helper.cc NEW/source/ns-3-dce/helper/linux-stack-helper.cc
*** ORIG/source/ns-3-dce/helper/linux-stack-helper.cc	2013-11-08 05:43:44.362638260 -0600
--- NEW/source/ns-3-dce/helper/linux-stack-helper.cc	2013-11-06 03:34:29.416131710 -0600
***************
*** 109,115 ****
      {
        Ptr<Node> node = *i;
        Ptr<Ipv4Linux> ipv4 = node->GetObject<Ipv4Linux> ();
!       ipv4->PopulateRoutingTable ();
      }
  #endif
  }
--- 117,126 ----
      {
        Ptr<Node> node = *i;
        Ptr<Ipv4Linux> ipv4 = node->GetObject<Ipv4Linux> ();
!       if(ipv4)
!         {
!           ipv4->PopulateRoutingTable ();
!         }
      }
  #endif
  }