diff -NurpP --minimal linux-2.6.27.6-vs2.3.0.35.12/net/core/dev.c linux-2.6.27.6-vs2.3.0.35.13/net/core/dev.c
--- linux-2.6.27.6-vs2.3.0.35.12/net/core/dev.c	2008-10-13 14:54:20.000000000 +0200
+++ linux-2.6.27.6-vs2.3.0.35.13/net/core/dev.c	2008-11-20 15:25:30.000000000 +0100
@@ -926,10 +926,15 @@ int dev_change_name(struct net_device *d
 		strlcpy(dev->name, newname, IFNAMSIZ);
 
 rollback:
-	err = device_rename(&dev->dev, dev->name);
-	if (err) {
-		memcpy(dev->name, oldname, IFNAMSIZ);
-		return err;
+	/* For now only devices in the initial network namespace
+	 * are in sysfs.
+	 */
+	if (net == &init_net) {
+		ret = device_rename(&dev->dev, dev->name);
+		if (ret) {
+			memcpy(dev->name, oldname, IFNAMSIZ);
+			return ret;
+		}
 	}
 
 	write_lock_bh(&dev_base_lock);
@@ -4391,6 +4396,15 @@ int dev_change_net_namespace(struct net_
 	if (dev->features & NETIF_F_NETNS_LOCAL)
 		goto out;
 
+#ifdef CONFIG_SYSFS
+	/* Don't allow real devices to be moved when sysfs
+	 * is enabled.
+	 */
+	err = -EINVAL;
+	if (dev->dev.parent)
+		goto out;
+#endif
+
 	/* Ensure the device has been registrered */
 	err = -EINVAL;
 	if (dev->reg_state != NETREG_REGISTERED)
@@ -4448,6 +4462,8 @@ int dev_change_net_namespace(struct net_
 	 */
 	dev_addr_discard(dev);
 
+	netdev_unregister_kobject(dev);
+
 	/* Actually switch the network namespace */
 	dev_net_set(dev, net);
 
@@ -4464,7 +4480,6 @@ int dev_change_net_namespace(struct net_
 	}
 
 	/* Fixup kobjects */
-	netdev_unregister_kobject(dev);
 	err = netdev_register_kobject(dev);
 	WARN_ON(err);
 
diff -NurpP --minimal linux-2.6.27.6-vs2.3.0.35.12/net/core/net-sysfs.c linux-2.6.27.6-vs2.3.0.35.13/net/core/net-sysfs.c
--- linux-2.6.27.6-vs2.3.0.35.12/net/core/net-sysfs.c	2008-10-13 14:52:09.000000000 +0200
+++ linux-2.6.27.6-vs2.3.0.35.13/net/core/net-sysfs.c	2008-11-20 15:21:32.000000000 +0100
@@ -440,6 +440,10 @@ void netdev_unregister_kobject(struct ne
 	struct device *dev = &(net->dev);
 
 	kobject_get(&dev->kobj);
+
+	if (dev_net(net) != &init_net)
+		return;
+
 	device_del(dev);
 }
 
@@ -465,6 +469,9 @@ int netdev_register_kobject(struct net_d
 #endif
 #endif /* CONFIG_SYSFS */
 
+	if (dev_net(net) != &init_net)
+		return 0;
+
 	return device_add(dev);
 }
 
diff -NurpP --minimal linux-2.6.27.6-vs2.3.0.35.12/net/Kconfig linux-2.6.27.6-vs2.3.0.35.13/net/Kconfig
--- linux-2.6.27.6-vs2.3.0.35.12/net/Kconfig	2008-10-13 14:52:09.000000000 +0200
+++ linux-2.6.27.6-vs2.3.0.35.13/net/Kconfig	2008-11-20 15:21:32.000000000 +0100
@@ -27,7 +27,7 @@ menu "Networking options"
 config NET_NS
 	bool "Network namespace support"
 	default n
-	depends on EXPERIMENTAL && !SYSFS && NAMESPACES
+	depends on EXPERIMENTAL && NAMESPACES
 	help
 	  Allow user space to create what appear to be multiple instances
 	  of the network stack.