--- ./kdm/backend/auth.c	2015-02-06 17:59:27.473734701 -0600
+++ ./kdm/backend/auth.c.orig	2015-02-06 18:46:13.072441136 -0600
@@ -44,6 +44,10 @@ 
 
 #include <sys/ioctl.h>
 
+#ifdef XDMCP
+# include <string.h>
+#endif
+
 #include "dm_socket.h"
 #ifdef DNETCONN
 # include <netdnet/dnetdb.h>
@@ -1075,10 +1079,28 @@ 
 static int
 convertAuthAddr(char *saddr, int *len, CARD8 **addr)
 {
+    static const unsigned char ipv6_lo[] = {
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01
+    };
+
+    static const unsigned char ipv4_lo[] = {
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x01
+    };
+
     int ret = convertAddr(saddr, len, addr);
-    if (ret == FamilyInternet &&
-            ((struct in_addr *)*addr)->s_addr == htonl(0x7F000001L))
-        ret = FamilyLocal;
+
+    if (ret == FamilyInternet) {
+        if (((struct in_addr *)*addr)->s_addr == htonl(0x7F000001L))
+            ret = FamilyLocal;
+    } else if (ret == FamilyInternet6) {
+	if (memcmp(*addr, ipv6_lo, sizeof ipv6_lo) == 0)
+            ret = FamilyLocal;
+        else if (memcmp(*addr, ipv4_lo, sizeof ipv4_lo) == 0)
+            ret = FamilyLocal;
+    }
+
     return ret;
 }