--- configure.in.orig	2006-06-19 08:08:48.000000000 +0000
+++ configure.in	2008-04-30 05:57:39.000000000 +0000
@@ -1405,6 +1405,26 @@
 AC_CACHE_CHECK(type of rtentry structure,ac_cv_RTENTRY_TYPE,
 [
 
+dnl 4.4 compatible but renamed on FreeBSD
+AC_TRY_COMPILE([
+#include <sys/types.h>
+#define KERNEL
+#define _KERNEL
+#include <sys/socket.h>
+#undef KERNEL
+#undef _KERNEL
+#include <net/route.h>
+],[
+
+#ifndef STRUCT_RTENTRY_HAS_RT_DST
+#define rt_dst rt_nodes->rn_key
+#endif
+
+  struct rtentry rt; 
+  rt.rt_nodes[0].rn_bit = 1;
+  rt.rt_dst;
+  ], ac_cv_RTENTRY_TYPE="BSD-4.4")
+
 # 4.4 compat
 AC_TRY_COMPILE([
 #ifdef HAVE_SYS_PARAM_H
