diff --git a/ChangeLog b/ChangeLog
index d52508b..af7429b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2010-08-19  Mats Erik Andersson <address@hidden>
+
+	* libinetutils/sockaddr_aux.h: New file.
+	* libinetutils/sockaddr_aux.c: New file.
+	* libinetutils/Makefile.am: Add sockaddr_aux.h and sockaddr_aux.c.
+	* libinetutils/tftpsubs.c (synchnet): Replace 'struct sockaddr_in' by
+	'struct sockaddr_storage'.
+
 2010-08-18  Giuseppe Scrivano  <address@hidden>
 
 	Under GNU/Linux print interfaces without an address with ifconfig -a.
diff --git a/libinetutils/Makefile.am b/libinetutils/Makefile.am
index 07e0566..a15b4e4 100644
--- a/libinetutils/Makefile.am
+++ b/libinetutils/Makefile.am
@@ -19,7 +19,8 @@
 
 noinst_LIBRARIES = libinetutils.a
 
-noinst_HEADERS = argcv.h libinetutils.h tftpsubs.h shishi_def.h
+noinst_HEADERS = argcv.h libinetutils.h tftpsubs.h shishi_def.h \
+		 sockaddr_aux.h
 
 EXTRA_DIST = logwtmp.c
 
@@ -29,6 +30,7 @@ libinetutils_a_SOURCES = \
  daemon.c\
  defauthors.c\
  des_rw.c\
+ sockaddr_aux.c \
  kcmd.c\
  krcmd.c\
  localhost.c\
diff --git a/libinetutils/sockaddr_aux.c b/libinetutils/sockaddr_aux.c
new file mode 100644
index 0000000..f882f6e
--- /dev/null
+++ b/libinetutils/sockaddr_aux.c
@@ -0,0 +1,98 @@
+/*
+  Copyright (C) 2010 Free Software Foundation, Inc.
+
+  This file is part of GNU Inetutils.
+
+  GNU Inetutils is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or (at
+  your option) any later version.
+
+  GNU Inetutils is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see `http://www.gnu.org/licenses/'.
+*/
+
+/* A collection of helpers intended to handle IPv6 and IPv4 simultaneously
+   in a transparent manner. An underlying use of 'struct sockaddr_storage'
+   is conceiled as 'struct sockaddr' in the call from an application.
+
+   The helper function resolves and manipulates this as 'struct sockaddr_in'
+   or as 'struct sockaddr_in6', depending on contents.
+
+   Mats Erik Andersson, August 2010
+*/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "sockaddr_aux.h"
+
+/*
+ * get_port
+ *
+ * Return: port number in host byte order.
+ * Input:  pointer to 'struct sockaddr'.
+ */
+in_port_t
+get_port (struct sockaddr *sa)
+{
+  switch (sa->sa_family)
+    {
+      case AF_INET:
+	return ntohs (((struct sockaddr_in *) sa)->sin_port);
+      case AF_INET6:
+	return ntohs (((struct sockaddr_in6 *) sa)->sin6_port);
+      default:
+	return 0;
+    }
+}
+
+/*
+ * set_port
+ *
+ * Input:  pointer to 'struct sockaddr', and
+ *         port number in host byte order.
+ */
+void
+set_port (struct sockaddr *sa, in_port_t port)
+{
+  switch (sa->sa_family)
+    {
+      case AF_INET:
+	(((struct sockaddr_in *) sa)->sin_port) = htons (port);
+	break;
+      case AF_INET6:
+	(((struct sockaddr_in6 *) sa)->sin6_port) = htons (port);
+      default:
+	break;
+    }
+}
+
+/*
+ * get_socklen
+ *
+ * Input:  pointer to 'struct sockaddr'.
+ * Return: exact address structure size for AF_INET and AF_INET6.
+ */
+socklen_t
+get_socklen (struct sockaddr *sa)
+{
+  switch (sa->sa_family)
+    {
+      case AF_INET:
+	return sizeof (struct sockaddr_in);
+	break;
+      case AF_INET6:
+	return sizeof (struct sockaddr_in6);
+	break;
+      default:
+	return sizeof (*sa);
+	break;
+    }
+}
diff --git a/libinetutils/sockaddr_aux.h b/libinetutils/sockaddr_aux.h
new file mode 100644
index 0000000..7e2545d
--- /dev/null
+++ b/libinetutils/sockaddr_aux.h
@@ -0,0 +1,43 @@
+/*
+  Copyright (C) 2010 Free Software Foundation, Inc.
+
+  This file is part of GNU Inetutils.
+
+  GNU Inetutils is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or (at
+  your option) any later version.
+
+  GNU Inetutils is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see `http://www.gnu.org/licenses/'.
+*/
+
+/* A collection of helpers intended to handle IPv6 and IPv4 simultaneously
+   in a transparent manner. An underlying use of 'struct sockaddr_storage'
+   is conceiled as 'struct sockaddr' in the call from an application.
+
+   The helper function resolves and manipulates this as 'struct sockaddr_in'
+   or as 'struct sockaddr_in6', depending on contents.
+
+   Mats Erik Andersson, August 2010
+*/
+
+/*
+ * Prototypes for address family independecy.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+in_port_t get_port (struct sockaddr *sa);
+
+void set_port (struct sockaddr *sa, in_port_t port);
+
+socklen_t get_socklen (struct sockaddr *sa);
diff --git a/libinetutils/tftpsubs.c b/libinetutils/tftpsubs.c
index 6eb0a09..371764b 100644
--- a/libinetutils/tftpsubs.c
+++ b/libinetutils/tftpsubs.c
@@ -287,7 +287,7 @@ synchnet (int f)
 {
   int i, j = 0;
   char rbuf[PKTSIZE];
-  struct sockaddr_in from;
+  struct sockaddr_storage from;
   socklen_t fromlen;
 
   while (1)