diff --git a/src/dhcp-manager/nm-dhcp-dhclient.c b/src/dhcp-manager/nm-dhcp-dhclient.c
index f35465976..ac7d9f58a 100644
--- a/src/dhcp-manager/nm-dhcp-dhclient.c
+++ b/src/dhcp-manager/nm-dhcp-dhclient.c
@@ -18,6 +18,10 @@
  * Copyright (C) 2005 - 2008 Red Hat, Inc.
  */
 
+#define _XOPEN_SOURCE
+#include <time.h>
+#undef _XOPEN_SOURCE
+
 #include <glib.h>
 #include <glib/gi18n.h>
 #include <dbus/dbus.h>
@@ -74,6 +78,206 @@ get_leasefile_for_iface (const char * iface, const char *uuid)
 	                        NM_DHCP_MANAGER_LEASE_FILE_EXT);
 }
 
+static void
+add_lease_option (GHashTable *hash, char *line)
+{
+	char *spc;
+
+	spc = strchr (line, ' ');
+	if (!spc) {
+		g_warning ("%s: line '%s' did not contain a space", __func__, line);
+		return;
+	}
+
+	/* If it's an 'option' line, split at second space */
+	if (g_str_has_prefix (line, "option ")) {
+		spc = strchr (spc + 1, ' ');
+		if (!spc) {
+			g_warning ("%s: option line '%s' did not contain a second space",
+			           __func__, line);
+			return;
+		}
+	}
+
+	/* Split the line at the space */
+	*spc = '\0';
+	spc++;
+
+	/* Kill the ';' at the end of the line, if any */
+	if (*(spc + strlen (spc) - 1) == ';')
+		*(spc + strlen (spc) - 1) = '\0';
+
+	/* Treat 'interface' specially */
+	if (g_str_has_prefix (line, "interface")) {
+		if (*(spc) == '"')
+			spc++; /* Jump past the " */
+		if (*(spc + strlen (spc) - 1) == '"')
+			*(spc + strlen (spc) - 1) = '\0';  /* Kill trailing " */
+	}
+
+	g_hash_table_insert (hash, g_strdup (line), g_strdup (spc));
+}
+
+GSList *
+nm_dhcp_client_get_lease_ip4_config (const char *iface, const char *uuid)
+{
+	GSList *parsed = NULL, *iter, *leases = NULL;
+	char *contents = NULL;
+	char *leasefile;
+	char **line, **split = NULL;
+	GHashTable *hash = NULL;
+
+	leasefile = get_leasefile_for_iface (iface, uuid);
+	if (!leasefile)
+		return NULL;
+
+	if (!g_file_test (leasefile, G_FILE_TEST_EXISTS))
+		goto out;
+
+	if (!g_file_get_contents (leasefile, &contents, NULL, NULL))
+		goto out;
+
+	split = g_strsplit_set (contents, "\n\r", -1);
+	g_free (contents);
+	if (!split)
+		goto out;
+
+	for (line = split; line && *line; line++) {
+		*line = g_strstrip (*line);
+
+		if (!strcmp (*line, "}")) {
+			/* Lease ends */
+			parsed = g_slist_append (parsed, hash);
+			hash = NULL;
+		} else if (!strcmp (*line, "lease {")) {
+			/* Beginning of a new lease */
+			if (hash) {
+				g_warning ("%s: lease file %s malformed; new lease started "
+				           "without ending previous lease",
+				           __func__, leasefile);
+				g_hash_table_destroy (hash);
+			}
+
+			hash = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
+		} else if (strlen (*line))
+			add_lease_option (hash, *line);
+	}
+	g_strfreev (split);
+
+	/* Check if the last lease in the file was properly ended */
+	if (hash) {
+		g_warning ("%s: lease file %s malformed; new lease started "
+		           "without ending previous lease",
+		           __func__, leasefile);
+		g_hash_table_destroy (hash);
+		hash = NULL;
+	}
+
+	for (iter = parsed; iter; iter = g_slist_next (iter)) {
+		NMIP4Config *ip4;
+		NMIP4Address *addr;
+		const char *data;
+		struct in_addr tmp;
+		guint32 prefix;
+		struct tm expire;
+
+		hash = iter->data;
+
+		/* Make sure this lease is for the interface we want */
+		data = g_hash_table_lookup (hash, "interface");
+		if (!data || strcmp (data, iface))
+			continue;
+
+		data = g_hash_table_lookup (hash, "expire");
+		if (data) {
+			time_t now_tt;
+			struct tm *now;
+
+			/* Read lease expiration (in UTC) */
+			if (!strptime (data, "%w %Y/%m/%d %H:%M:%S", &expire)) {
+				g_warning ("%s: couldn't parse expire time '%s'",
+				           __func__, data);
+				continue;
+			}
+
+			now_tt = time (NULL);
+			now = gmtime(&now_tt);
+
+			/* Ignore this lease if it's already expired */
+			if (expire.tm_year < now->tm_year)
+				continue;
+			else if (expire.tm_year == now->tm_year) {
+				if (expire.tm_mon < now->tm_mon)
+					continue;
+				else if (expire.tm_mon == now->tm_mon) {
+					if (expire.tm_mday < now->tm_mday)
+						continue;
+					else if (expire.tm_mday == now->tm_mday) {
+						if (expire.tm_hour < now->tm_hour)
+							continue;
+						else if (expire.tm_hour == now->tm_hour) {
+							if (expire.tm_min < now->tm_min)
+								continue;
+							else if (expire.tm_min == now->tm_min) {
+								if (expire.tm_sec <= now->tm_sec)
+									continue;
+							}
+						}
+					}
+				}
+			}
+			/* If we get this far, the lease hasn't expired */
+		}
+
+		data = g_hash_table_lookup (hash, "fixed-address");
+		if (!data)
+			continue;
+
+		ip4 = nm_ip4_config_new ();
+		addr = nm_ip4_address_new ();
+
+		/* IP4 address */
+		if (!inet_pton (AF_INET, data, &tmp)) {
+			g_warning ("%s: couldn't parse IP4 address '%s'", __func__, data);
+			goto error;
+		}
+		nm_ip4_address_set_address (addr, tmp.s_addr);
+
+		/* Netmask */
+		data = g_hash_table_lookup (hash, "option subnet-mask");
+		if (!data)
+			data = "255.255.255.0"; /* FIXME: assume class C? */
+		if (!inet_pton (AF_INET, data, &tmp)) {
+			g_warning ("%s: couldn't parse IP4 subnet mask '%s'", __func__, data);
+			goto error;
+		}
+		prefix = nm_utils_ip4_netmask_to_prefix (tmp.s_addr);
+		nm_ip4_address_set_prefix (addr, prefix);
+
+		/* Gateway */
+		data = g_hash_table_lookup (hash, "option routers");
+		if (data) {
+			if (!inet_pton (AF_INET, data, &tmp)) {
+				g_warning ("%s: couldn't parse IP4 gateway '%s'", __func__, data);
+				goto error;
+			}
+			nm_ip4_address_set_gateway (addr, tmp.s_addr);
+		}
+
+		nm_ip4_config_take_address (ip4, addr);
+		leases = g_slist_append (leases, ip4);
+		continue;
+
+	error:
+		nm_ip4_address_unref (addr);
+		g_object_unref (ip4);
+	}
+
+out:
+	g_slist_foreach (parsed, (GFunc) g_hash_table_destroy, NULL);
+	g_free (leasefile);
+	return leases;
+}
 
 
 #define DHCP_CLIENT_ID_TAG "send dhcp-client-identifier"
diff --git a/src/dhcp-manager/nm-dhcp-dhcpcd.c b/src/dhcp-manager/nm-dhcp-dhcpcd.c
index a6ce8d21e..a8d929a52 100644
--- a/src/dhcp-manager/nm-dhcp-dhcpcd.c
+++ b/src/dhcp-manager/nm-dhcp-dhcpcd.c
@@ -49,6 +49,11 @@ get_pidfile_for_iface (const char * iface)
 	                        NM_DHCP_MANAGER_PID_FILE_EXT);
 }
 
+GSList *
+nm_dhcp_client_get_lease_ip4_config (const char *iface, const char *uuid)
+{
+	return NULL;
+}
 
 static void
 dhcpcd_child_setup (gpointer user_data G_GNUC_UNUSED)
diff --git a/src/dhcp-manager/nm-dhcp-manager.c b/src/dhcp-manager/nm-dhcp-manager.c
index bdd2695b2..f099ea289 100644
--- a/src/dhcp-manager/nm-dhcp-manager.c
+++ b/src/dhcp-manager/nm-dhcp-manager.c
@@ -1121,3 +1121,16 @@ nm_dhcp_manager_set_hostname_provider (NMDHCPManager *manager,
 		g_object_weak_ref (G_OBJECT (provider), hostname_provider_destroyed, manager);
 	}
 }
+
+GSList *
+nm_dhcp_manager_get_lease_ip4_config (NMDHCPManager *self,
+                                      const char *iface,
+                                      const char *uuid)
+{
+	g_return_val_if_fail (NM_IS_DHCP_MANAGER (self), NULL);
+	g_return_val_if_fail (iface != NULL, NULL);
+	g_return_val_if_fail (uuid != NULL, NULL);
+
+	return nm_dhcp_client_get_lease_ip4_config (iface, uuid);
+}
+
diff --git a/src/dhcp-manager/nm-dhcp-manager.h b/src/dhcp-manager/nm-dhcp-manager.h
index 6880a2336..124008493 100644
--- a/src/dhcp-manager/nm-dhcp-manager.h
+++ b/src/dhcp-manager/nm-dhcp-manager.h
@@ -107,6 +107,10 @@ gboolean       nm_dhcp_manager_foreach_dhcp4_option (NMDHCPManager *self,
                                                      GHFunc func,
                                                      gpointer user_data);
 
+GSList *       nm_dhcp_manager_get_lease_ip4_config (NMDHCPManager *self,
+                                                     const char *iface,
+                                                     const char *uuid);
+
 /* The following are implemented by the DHCP client backends */
 GPid           nm_dhcp_client_start                 (NMDHCPDevice *device,
                                                      const char *uuid,
@@ -118,6 +122,9 @@ gboolean       nm_dhcp_client_process_classless_routes (GHashTable *options,
                                                         NMIP4Config *ip4_config,
                                                         guint32 *gwaddr);
 
+GSList *       nm_dhcp_client_get_lease_ip4_config  (const char *iface,
+                                                     const char *uuid);
+
 /* Test functions */
 NMIP4Config *nm_dhcp_manager_options_to_ip4_config (const char *iface,
                                                     GHashTable *options);
diff --git a/src/nm-device-ethernet.c b/src/nm-device-ethernet.c
index 759a183ea..2c68f790d 100644
--- a/src/nm-device-ethernet.c
+++ b/src/nm-device-ethernet.c
@@ -53,6 +53,7 @@
 #include "ppp-manager/nm-ppp-manager.h"
 #include "nm-utils.h"
 #include "nm-properties-changed-signal.h"
+#include "nm-dhcp-manager.h"
 
 #include "nm-device-ethernet-glue.h"
 
@@ -280,8 +281,8 @@ constructor (GType type,
 	guint32 caps;
 
 	object = G_OBJECT_CLASS (nm_device_ethernet_parent_class)->constructor (type,
-																   n_construct_params,
-																   construct_params);
+	                                                                        n_construct_params,
+	                                                                        construct_params);
 	if (!object)
 		return NULL;
 
@@ -1472,6 +1473,196 @@ spec_match_list (NMDevice *device, const GSList *specs)
 	return matched;
 }
 
+static gboolean
+wired_match_config (NMDevice *self, NMConnection *connection)
+{
+	NMSettingWired *s_wired;
+	struct ether_addr ether;
+	const GByteArray *s_ether;
+
+	s_wired = (NMSettingWired *) nm_connection_get_setting (connection, NM_TYPE_SETTING_WIRED);
+	if (!s_wired)
+		return FALSE;
+
+	/* MAC address check */
+	s_ether = nm_setting_wired_get_mac_address (s_wired);
+	if (s_ether) {
+		nm_device_ethernet_get_address (NM_DEVICE_ETHERNET (self), &ether);
+
+		if (memcmp (s_ether->data, ether.ether_addr_octet, ETH_ALEN))
+			return FALSE;
+	}
+
+	return TRUE;
+}
+
+typedef struct {
+	int ifindex;
+	NMIP4Address *addr;
+	gboolean found;
+} AddrData;
+
+static void
+check_one_address (struct nl_object *object, void *user_data)
+{
+	AddrData *data = user_data;
+	struct rtnl_addr *addr = (struct rtnl_addr *) object;
+	struct nl_addr *local;
+	struct in_addr tmp;
+
+	if (rtnl_addr_get_ifindex (addr) != data->ifindex)
+		return;
+	if (rtnl_addr_get_family (addr) != AF_INET)
+		return;
+
+	if (nm_ip4_address_get_prefix (data->addr) != rtnl_addr_get_prefixlen (addr))
+		return;
+
+	local = rtnl_addr_get_local (addr);
+	if (nl_addr_get_family (local) != AF_INET)
+		return;
+	if (nl_addr_get_len (local) != sizeof (struct in_addr))
+		return;
+	if (!nl_addr_get_binary_addr (local))
+		return;
+
+	memcpy (&tmp, nl_addr_get_binary_addr (local), nl_addr_get_len (local));
+	if (tmp.s_addr != nm_ip4_address_get_address (data->addr))
+		return;
+
+	/* Yay, found it */
+	data->found = TRUE;
+}
+
+static gboolean
+ip4_match_config (NMDevice *self, NMConnection *connection)
+{
+	NMSettingIP4Config *s_ip4;
+	NMSettingConnection *s_con;
+	struct nl_handle *nlh = NULL;
+	struct nl_cache *addr_cache = NULL;
+	int i, num;
+	GSList *leases, *iter;
+	NMDHCPManager *dhcp_mgr;
+	const char *method;
+	int ifindex;
+	AddrData check_data;
+
+	ifindex = nm_device_ethernet_get_ifindex (NM_DEVICE_ETHERNET (self));
+
+	s_con = (NMSettingConnection *) nm_connection_get_setting (connection, NM_TYPE_SETTING_CONNECTION);
+	g_assert (s_con);
+	g_assert (nm_setting_connection_get_uuid (s_con));
+
+	s_ip4 = (NMSettingIP4Config *) nm_connection_get_setting (connection, NM_TYPE_SETTING_IP4_CONFIG);
+	if (!s_ip4)
+		return FALSE;
+
+	/* Read all the device's IP addresses */
+	nlh = nm_netlink_get_default_handle ();
+	if (!nlh)
+		return FALSE;
+
+	addr_cache = rtnl_addr_alloc_cache (nlh);
+	if (!addr_cache)
+		return FALSE;
+	nl_cache_mngt_provide (addr_cache);
+
+	/* Get any saved leases that apply to this connection */
+	dhcp_mgr = nm_dhcp_manager_get ();
+	leases = nm_dhcp_manager_get_lease_ip4_config (dhcp_mgr,
+	                                               nm_device_get_iface (self),
+	                                               nm_setting_connection_get_uuid (s_con));
+	g_object_unref (dhcp_mgr);
+
+	method = nm_setting_ip4_config_get_method (s_ip4);
+	if (!strcmp (method, NM_SETTING_IP4_CONFIG_METHOD_AUTO)) {
+		gboolean found = FALSE;
+
+		/* Find at least one lease's address on the device */
+		for (iter = leases; iter; iter = g_slist_next (iter)) {
+			NMIP4Config *addr = iter->data;
+
+			memset (&check_data, 0, sizeof (check_data));
+			check_data.ifindex = ifindex;
+			check_data.found = FALSE;
+			check_data.addr = nm_ip4_config_get_address (addr, 0);
+
+			nl_cache_foreach (addr_cache, check_one_address, &check_data);
+			if (check_data.found) {
+				found = TRUE; /* Yay, device has same address as a lease */
+				break;
+			}
+		}
+		g_slist_foreach (leases, (GFunc) g_object_unref, NULL);
+		g_slist_free (leases);
+		return found;
+	} else {
+		/* Maybe the connection used to be DHCP and there are stale leases; ignore them */
+		g_slist_foreach (leases, (GFunc) g_object_unref, NULL);
+		g_slist_free (leases);
+	}
+
+	/* 'shared' and 'link-local' aren't supported methods because 'shared'
+	 * requires too much iptables and dnsmasq state to be reclaimed, and
+	 * avahi-autoipd isn't smart enough to allow the link-local address to be
+	 * determined at any point other than when it was first assigned.
+	 */
+	if (strcmp (method, NM_SETTING_IP4_CONFIG_METHOD_MANUAL))
+		return FALSE;
+
+	/* Everything below for static addressing */
+
+	/* Find all IP4 addresses of this connection in the device's address list */
+	num = nm_setting_ip4_config_get_num_addresses (s_ip4);
+	for (i = 0; i < num; i++) {
+		memset (&check_data, 0, sizeof (check_data));
+		check_data.ifindex = ifindex;
+		check_data.found = FALSE;
+		check_data.addr = nm_setting_ip4_config_get_address (s_ip4, i);
+
+		nl_cache_foreach (addr_cache, check_one_address, &check_data);
+		if (!check_data.found)
+			return FALSE;
+	}
+
+	/* Success; all the connection's static IP addresses are assigned to the device */
+	return TRUE;
+}
+
+static NMConnection *
+connection_match_config (NMDevice *self, const GSList *connections)
+{
+	GSList *iter;
+	NMSettingConnection *s_con;
+
+	for (iter = (GSList *) connections; iter; iter = g_slist_next (iter)) {
+		NMConnection *candidate = NM_CONNECTION (iter->data);
+
+		s_con = (NMSettingConnection *) nm_connection_get_setting (candidate, NM_TYPE_SETTING_CONNECTION);
+		g_assert (s_con);
+		if (strcmp (nm_setting_connection_get_connection_type (s_con), NM_SETTING_WIRED_SETTING_NAME))
+			continue;
+
+		/* Can't assume 802.1x or PPPoE connections; they have too much state
+		 * that's impossible to get on-the-fly from PPPoE or the supplicant.
+		 */
+		if (   nm_connection_get_setting (candidate, NM_TYPE_SETTING_802_1X)
+		    || nm_connection_get_setting (candidate, NM_TYPE_SETTING_PPPOE))
+			continue;
+
+		if (!wired_match_config (self, candidate))
+			continue;
+
+		if (!ip4_match_config (self, candidate))
+			continue;
+
+		return candidate;
+	}
+
+	return NULL;
+}
+
 static void
 dispose (GObject *object)
 {
@@ -1587,6 +1778,7 @@ nm_device_ethernet_class_init (NMDeviceEthernetClass *klass)
 	parent_class->act_stage4_get_ip4_config = real_act_stage4_get_ip4_config;
 	parent_class->deactivate_quickly = real_deactivate_quickly;
 	parent_class->spec_match_list = spec_match_list;
+	parent_class->connection_match_config = connection_match_config;
 
 	/* properties */
 	g_object_class_install_property
diff --git a/src/nm-device-interface.c b/src/nm-device-interface.c
index 5647adb42..7f287a869 100644
--- a/src/nm-device-interface.c
+++ b/src/nm-device-interface.c
@@ -282,8 +282,29 @@ gboolean
 nm_device_interface_spec_match_list (NMDeviceInterface *device,
                                      const GSList *specs)
 {
+	g_return_val_if_fail (NM_IS_DEVICE_INTERFACE (device), FALSE);
+
 	if (NM_DEVICE_INTERFACE_GET_INTERFACE (device)->spec_match_list)
 		return NM_DEVICE_INTERFACE_GET_INTERFACE (device)->spec_match_list (device, specs);
 	return FALSE;
 }
 
+NMConnection *
+nm_device_interface_connection_match_config (NMDeviceInterface *device,
+                                             const GSList *connections)
+{
+	g_return_val_if_fail (NM_IS_DEVICE_INTERFACE (device), NULL);
+
+	if (NM_DEVICE_INTERFACE_GET_INTERFACE (device)->connection_match_config)
+		return NM_DEVICE_INTERFACE_GET_INTERFACE (device)->connection_match_config (device, connections);
+	return NULL;
+}
+
+gboolean
+nm_device_interface_can_assume_connection (NMDeviceInterface *device)
+{
+	g_return_val_if_fail (NM_IS_DEVICE_INTERFACE (device), FALSE);
+
+	return !!NM_DEVICE_INTERFACE_GET_INTERFACE (device)->connection_match_config;
+}
+
diff --git a/src/nm-device-interface.h b/src/nm-device-interface.h
index 760cccacc..97a95da47 100644
--- a/src/nm-device-interface.h
+++ b/src/nm-device-interface.h
@@ -88,6 +88,8 @@ struct _NMDeviceInterface {
 
 	gboolean (*spec_match_list) (NMDeviceInterface *device, const GSList *specs);
 
+	NMConnection * (*connection_match_config) (NMDeviceInterface *device, const GSList *specs);
+
 	/* Signals */
 	void (*state_changed) (NMDeviceInterface *device,
 	                       NMDeviceState new_state,
@@ -115,4 +117,9 @@ NMDeviceState nm_device_interface_get_state (NMDeviceInterface *device);
 gboolean nm_device_interface_spec_match_list (NMDeviceInterface *device,
                                               const GSList *specs);
 
+NMConnection * nm_device_interface_connection_match_config (NMDeviceInterface *device,
+                                                            const GSList *connections);
+
+gboolean nm_device_interface_can_assume_connection (NMDeviceInterface *device);
+
 #endif /* NM_DEVICE_INTERFACE_H */
diff --git a/src/nm-device.c b/src/nm-device.c
index 6f7423b38..56634ef8f 100644
--- a/src/nm-device.c
+++ b/src/nm-device.c
@@ -121,7 +121,8 @@ static gboolean nm_device_activate (NMDeviceInterface *device,
                                     NMActRequest *req,
                                     GError **error);
 static void nm_device_deactivate (NMDeviceInterface *device, NMDeviceStateReason reason);
-static gboolean nm_device_spec_match_list (NMDeviceInterface *device, const GSList *specs);
+static gboolean spec_match_list (NMDeviceInterface *device, const GSList *specs);
+static NMConnection *connection_match_config (NMDeviceInterface *device, const GSList *connections);
 
 static void nm_device_activate_schedule_stage5_ip_config_commit (NMDevice *self);
 
@@ -139,7 +140,8 @@ device_interface_init (NMDeviceInterface *device_interface_class)
 	device_interface_class->check_connection_compatible = check_connection_compatible;
 	device_interface_class->activate = nm_device_activate;
 	device_interface_class->deactivate = nm_device_deactivate;
-	device_interface_class->spec_match_list = nm_device_spec_match_list;
+	device_interface_class->spec_match_list = spec_match_list;
+	device_interface_class->connection_match_config = connection_match_config;
 }
 
 
@@ -2202,25 +2204,45 @@ dispose (GObject *object)
 {
 	NMDevice *self = NM_DEVICE (object);
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
+	gboolean take_down = TRUE;
 
 	if (priv->disposed || !priv->initialized)
 		goto out;
 
 	priv->disposed = TRUE;
 
+	/* Don't down can-assume-connection capable devices that are activated with
+	 * a connection that can be assumed.
+	 */
+	if (nm_device_interface_can_assume_connection (NM_DEVICE_INTERFACE (self))
+		&& (nm_device_get_state (self) == NM_DEVICE_STATE_ACTIVATED)) {
+		NMConnection *connection;
+	    NMSettingIP4Config *s_ip4;
+		const char *method = NULL;
+
+		/* Only system connections can be left up */
+		connection = nm_act_request_get_connection (priv->act_request);
+		if (   connection
+		    && (nm_connection_get_scope (connection) == NM_CONNECTION_SCOPE_SYSTEM)) {
+
+			/* Only static or DHCP connections can be left up */
+			s_ip4 = (NMSettingIP4Config *) nm_connection_get_setting (connection, NM_TYPE_SETTING_IP4_CONFIG);
+			g_assert (s_ip4);
+
+			method = nm_setting_ip4_config_get_method (s_ip4);
+			if (   !method
+			    || !strcmp (method, NM_SETTING_IP4_CONFIG_METHOD_AUTO)
+			    || !strcmp (method, NM_SETTING_IP4_CONFIG_METHOD_MANUAL))
+				take_down = FALSE;
+		}
+	}
+
 	if (priv->failed_to_disconnected_id) {
 		g_source_remove (priv->failed_to_disconnected_id);
 		priv->failed_to_disconnected_id = 0;
 	}
 
-	/* 
-	 * In dispose, you are supposed to free all types referenced from this
-	 * object which might themselves hold a reference to self. Generally,
-	 * the most simple solution is to unref all members on which you own a 
-	 * reference.
-	 */
-
-	if (priv->managed) {
+	if (priv->managed && take_down) {
 		NMDeviceStateReason ignored = NM_DEVICE_STATE_REASON_NONE;
 
 		nm_device_take_down (self, FALSE, NM_DEVICE_STATE_REASON_REMOVED);
@@ -2231,7 +2253,8 @@ dispose (GObject *object)
 
 	activation_source_clear (self, TRUE);
 
-	nm_device_set_use_dhcp (self, FALSE);
+	if (!take_down)
+		nm_device_set_use_dhcp (self, FALSE);
 
 	if (priv->dnsmasq_manager) {
 		if (priv->dnsmasq_state_id) {
@@ -2577,7 +2600,7 @@ nm_device_set_managed (NMDevice *device,
 }
 
 static gboolean
-nm_device_spec_match_list (NMDeviceInterface *device, const GSList *specs)
+spec_match_list (NMDeviceInterface *device, const GSList *specs)
 {
 	NMDevice *self;
 
@@ -2590,6 +2613,16 @@ nm_device_spec_match_list (NMDeviceInterface *device, const GSList *specs)
 	return FALSE;
 }
 
+static NMConnection *
+connection_match_config (NMDeviceInterface *device, const GSList *connections)
+{
+	g_return_val_if_fail (device != NULL, FALSE);
+
+	if (NM_DEVICE_GET_CLASS (device)->connection_match_config)
+		return NM_DEVICE_GET_CLASS (device)->connection_match_config (NM_DEVICE (device), connections);
+	return NULL;
+}
+
 void
 nm_device_set_dhcp_timeout (NMDevice *device, guint32 timeout)
 {
diff --git a/src/nm-device.h b/src/nm-device.h
index 31c58fb54..f3d63235e 100644
--- a/src/nm-device.h
+++ b/src/nm-device.h
@@ -106,6 +106,8 @@ typedef struct {
 	gboolean		(* can_interrupt_activation)		(NMDevice *self);
 
 	gboolean        (* spec_match_list)     (NMDevice *self, const GSList *specs);
+
+	NMConnection *  (* connection_match_config) (NMDevice *self, const GSList *connections);
 } NMDeviceClass;
 
 
diff --git a/src/nm-manager.c b/src/nm-manager.c
index 731589c40..87338a10d 100644
--- a/src/nm-manager.c
+++ b/src/nm-manager.c
@@ -348,12 +348,24 @@ manager_device_state_changed (NMDevice *device,
 
 /* Removes a device from a device list; returns the start of the new device list */
 static GSList *
-remove_one_device (NMManager *manager, GSList *list, NMDevice *device)
+remove_one_device (NMManager *manager,
+                   GSList *list,
+                   NMDevice *device,
+                   gboolean quitting)
 {
 	NMManagerPrivate *priv = NM_MANAGER_GET_PRIVATE (manager);
 
-	if (nm_device_get_managed (device))
-		nm_device_set_managed (device, FALSE, NM_DEVICE_STATE_REASON_REMOVED);
+	if (nm_device_get_managed (device)) {
+		gboolean unmanage = !quitting;
+
+		/* Don't unmanage active assume-connection-capable devices at shutdown */
+		if (   nm_device_interface_can_assume_connection (NM_DEVICE_INTERFACE (device))
+		    && nm_device_get_state (device) == NM_DEVICE_STATE_ACTIVATED)
+			unmanage = FALSE;
+
+		if (unmanage)
+			nm_device_set_managed (device, FALSE, NM_DEVICE_STATE_REASON_REMOVED);
+	}
 
 	g_signal_handlers_disconnect_by_func (device, manager_device_state_changed, manager);
 
@@ -372,7 +384,7 @@ modem_removed (NMModemManager *modem_manager,
 	NMManager *self = NM_MANAGER (user_data);
 	NMManagerPrivate *priv = NM_MANAGER_GET_PRIVATE (self);
 
-	priv->devices = remove_one_device (self, priv->devices, modem);
+	priv->devices = remove_one_device (self, priv->devices, modem, FALSE);
 }
 
 static void
@@ -1153,6 +1165,10 @@ add_device (NMManager *self, NMDevice *device)
 	char *path;
 	static guint32 devcount = 0;
 	const GSList *unmanaged_specs;
+	GSList *connections = NULL;
+	NMConnection *existing;
+	GHashTableIter iter;
+	gpointer value;
 
 	priv->devices = g_slist_append (priv->devices, device);
 
@@ -1189,6 +1205,16 @@ add_device (NMManager *self, NMDevice *device)
 	nm_info ("(%s): exported as %s", iface, path);
 	g_free (path);
 
+	/* Check if we should assume the device's active connection by matching its
+	 * config with an existing system connection.
+	 */
+	g_hash_table_iter_init (&iter, priv->system_connections);
+	while (g_hash_table_iter_next (&iter, NULL, &value))
+		connections = g_slist_append (connections, value);
+	existing = nm_device_interface_connection_match_config (NM_DEVICE_INTERFACE (device),
+	                                                        (const GSList *) connections);
+	g_slist_free (connections);
+
 	/* Start the device if it's supposed to be managed */
 	unmanaged_specs = nm_sysconfig_settings_get_unmanaged_specs (priv->sys_settings);
 	if (!priv->sleeping && !nm_device_interface_spec_match_list (NM_DEVICE_INTERFACE (device), unmanaged_specs))
@@ -1302,7 +1328,7 @@ bluez_manager_resync_devices (NMManager *self)
 		priv->devices = keep;
 
 		while (g_slist_length (gone))
-			gone = remove_one_device (self, gone, NM_DEVICE (gone->data));
+			gone = remove_one_device (self, gone, NM_DEVICE (gone->data), FALSE);
 	} else {
 		g_slist_free (keep);
 		g_slist_free (gone);
@@ -1372,7 +1398,7 @@ bluez_manager_bdaddr_removed_cb (NMBluezManager *bluez_mgr,
 		NMDevice *device = NM_DEVICE (iter->data);
 
 		if (!strcmp (nm_device_get_udi (device), object_path)) {
-			priv->devices = remove_one_device (self, priv->devices, device);
+			priv->devices = remove_one_device (self, priv->devices, device, FALSE);
 			break;
 		}
 	}
@@ -1433,8 +1459,7 @@ udev_device_removed_cb (NMUdevManager *manager,
 	ifindex = g_udev_device_get_property_as_int (udev_device, "IFINDEX");
 	device = find_device_by_ifindex (self, ifindex);
 	if (device)
-		priv->devices = remove_one_device (self, priv->devices, device);
-
+		priv->devices = remove_one_device (self, priv->devices, device, FALSE);
 }
 
 static void
@@ -2522,7 +2547,7 @@ dispose (GObject *object)
 	while (g_slist_length (priv->devices)) {
 		NMDevice *device = NM_DEVICE (priv->devices->data);
 
-		priv->devices = remove_one_device (manager, priv->devices, device);
+		priv->devices = remove_one_device (manager, priv->devices, device, TRUE);
 	}
 
 	user_destroy_connections (manager);