Index: sys/netinet/in.h
===================================================================
--- sys/netinet/in.h
+++ sys/netinet/in.h
@@ -369,12 +369,15 @@
 #define	IN_CLASSD_HOST		0x0fffffff	/* routing needn't know.    */
 #define	IN_MULTICAST(i)		IN_CLASSD(i)
 
-#define	IN_EXPERIMENTAL(i)	(((in_addr_t)(i) & 0xf0000000) == 0xf0000000)
+/* Open IN_EXPERMINTAL up so that only 255.255.255/24 is restricted */
+#define	IN_EXPERIMENTAL(i)	(((in_addr_t)(i) & 0xffffff00) == 0xffffff00)
 #define	IN_BADCLASS(i)		(((in_addr_t)(i) & 0xf0000000) == 0xf0000000)
 
 #define IN_LINKLOCAL(i)		(((in_addr_t)(i) & 0xffff0000) == 0xa9fe0000)
-#define IN_LOOPBACK(i)		(((in_addr_t)(i) & 0xff000000) == 0x7f000000)
-#define IN_ZERONET(i)		(((in_addr_t)(i) & 0xff000000) == 0)
+/* Open IN_LOOPBACK up so that only 127.0/16 is restricted */
+#define IN_LOOPBACK(i)		(((in_addr_t)(i) & 0xffff0000) == 0x7f000000)
+/* Open IN_ZERONET up so that only 0/24 is restricted  */
+#define IN_ZERONET(i)		(((in_addr_t)(i) & 0xffffff00) == 0)
 
 #define	IN_PRIVATE(i)	((((in_addr_t)(i) & 0xff000000) == 0x0a000000) || \
 			 (((in_addr_t)(i) & 0xfff00000) == 0xac100000) || \