Index: /trunk/src/VBox/NetworkServices/NAT/pxping.c
===================================================================
--- /trunk/src/VBox/NetworkServices/NAT/pxping.c	(revision 51681)
+++ /trunk/src/VBox/NetworkServices/NAT/pxping.c	(revision 51682)
@@ -259,5 +259,5 @@
     if (g_pxping.sock4 != INVALID_SOCKET) {
 #ifdef DF_WITH_IP_HDRINCL
-        g_pxping.hdrincl = -1;
+        g_pxping.hdrincl = 0;
 #else
         g_pxping.df = -1;