--- 2.4.27/include/linux/in.h	2004-05-28 17:15:37.000000000 +0300
+++ 2.4.27.hacked/include/linux/in.h	2005-03-07 09:53:02.000000000 +0200
@@ -226,7 +226,7 @@
 
 /* Address to loopback in software to local host.  */
 #define	INADDR_LOOPBACK		0x7f000001	/* 127.0.0.1   */
-#define	IN_LOOPBACK(a)		((((long int) (a)) & 0xff000000) == 0x7f000000)
+#define	IN_LOOPBACK(a)		((((long int) (a)) & 0xffff0000) == 0x7f000000)
 
 /* Defines for Multicast INADDR */
 #define INADDR_UNSPEC_GROUP   	0xe0000000U	/* 224.0.0.0   */
@@ -240,7 +240,7 @@
 
 #ifdef __KERNEL__
 /* Some random defines to make it easier in the kernel.. */
-#define LOOPBACK(x)	(((x) & htonl(0xff000000)) == htonl(0x7f000000))
+#define LOOPBACK(x)	(((x) & htonl(0xffff0000)) == htonl(0x7f000000))
 #define MULTICAST(x)	(((x) & htonl(0xf0000000)) == htonl(0xe0000000))
 #define BADCLASS(x)	(((x) & htonl(0xf0000000)) == htonl(0xf0000000))
 #define ZERONET(x)	(((x) & htonl(0xff000000)) == htonl(0x00000000))