diff -rup apr.orig/include/apr.hw apr/include/apr.hw
--- apr.orig/include/apr.hw	2007-10-23 23:41:58.000000000 +0200
+++ apr/include/apr.hw	2008-04-24 18:51:29.089077200 +0200
@@ -76,9 +76,11 @@
 #endif
 #ifndef _WIN32_WINNT
 
-/* Restrict the server to a subset of Windows NT 4.0 header files by default
+/* Restrict the server to a subset of Windows 2000 header files by default
+ *
+ * In order to use the MCAST API - 0x0501 is required!
  */
-#define _WIN32_WINNT 0x0400
+#define _WIN32_WINNT 0x0501 /* _WIN32_WINNT_WINXP */
 #endif
 #ifndef NOUSER
 #define NOUSER
@@ -217,7 +219,7 @@
 #define APR_HAVE_IN_ADDR        1
 #define APR_HAVE_INET_ADDR      1
 #define APR_HAVE_INET_NETWORK   0
-#define APR_HAVE_IPV6           0
+#define APR_HAVE_IPV6           1
 #define APR_HAVE_MEMMOVE        1
 #define APR_HAVE_SETRLIMIT      0
 #define APR_HAVE_SIGACTION      0
diff -rup apr.orig/network_io/unix/multicast.c apr/network_io/unix/multicast.c
--- apr.orig/network_io/unix/multicast.c	2007-11-14 11:01:40.000000000 +0100
+++ apr/network_io/unix/multicast.c	2008-04-24 18:48:01.542202200 +0200
@@ -135,8 +135,8 @@ static apr_status_t do_mcast(int type, a
     apr_status_t rv = APR_SUCCESS;
 #if APR_HAVE_IPV6
     struct ipv6_mreq mip6;
-#endif
-#if MCAST_JOIN_SOURCE_GROUP
+#endif
+#ifdef GROUP_FILTER_SIZE
     struct group_source_req mip;
     int ip_proto;
 #endif
@@ -148,7 +148,7 @@ static apr_status_t do_mcast(int type, a
     }
 
     if (source != NULL) {
-#if MCAST_JOIN_SOURCE_GROUP
+#ifdef GROUP_FILTER_SIZE
         if (sock_is_ipv4(sock)) {
             ip_proto = IPPROTO_IP;
         }