diff --git a/connection_manager.cc b/connection_manager.cc
index 4063f24..a048f5f 100644
--- a/connection_manager.cc
+++ b/connection_manager.cc
@@ -138,8 +138,11 @@
   if (!default_service_path.IsValid())
     return false;
   // Shill uses the "/" service path to indicate that it is not connected.
-  if (default_service_path.value() == "/")
-    return false;
+  if (default_service_path.value() == "/") {
+    *out_type = ConnectionType::kDisconnected;
+    *out_tethering = ConnectionTethering::kUnknown;
+    return true;
+  }
   TEST_AND_RETURN_FALSE(
       GetServicePathProperties(default_service_path, out_type, out_tethering));
   return true;
diff --git a/connection_manager.h b/connection_manager.h
index dc563ef..d8527a3 100644
--- a/connection_manager.h
+++ b/connection_manager.h
@@ -47,8 +47,8 @@
   bool IsAllowedConnectionTypesForUpdateSet() const override;
 
  private:
-  // Returns (via out_path) the default network path, or empty string if
-  // there's no network up. Returns true on success.
+  // Returns (via out_path) the default network path, or "/" if there's no
+  // network up. Returns true on success.
   bool GetDefaultServicePath(dbus::ObjectPath* out_path);
 
   bool GetServicePathProperties(const dbus::ObjectPath& path,
diff --git a/connection_manager_unittest.cc b/connection_manager_unittest.cc
index 85b8c57..7cd858d 100644
--- a/connection_manager_unittest.cc
+++ b/connection_manager_unittest.cc
@@ -75,6 +75,9 @@
       const char* service_type,
       const char* physical_technology,
       ConnectionType expected_type);
+
+  void TestWithServiceDisconnected(ConnectionType expected_type);
+
   void TestWithServiceTethering(
       const char* service_tethering,
       ConnectionTethering expected_tethering);
@@ -170,6 +173,18 @@
       fake_shill_proxy_->GetManagerProxy());
 }
 
+void ConnectionManagerTest::TestWithServiceDisconnected(
+    ConnectionType expected_type) {
+  SetManagerReply("/", true);
+
+  ConnectionType type;
+  ConnectionTethering tethering;
+  EXPECT_TRUE(cmut_.GetConnectionProperties(&type, &tethering));
+  EXPECT_EQ(expected_type, type);
+  testing::Mock::VerifyAndClearExpectations(
+      fake_shill_proxy_->GetManagerProxy());
+}
+
 TEST_F(ConnectionManagerTest, SimpleTest) {
   TestWithServiceType(shill::kTypeEthernet, nullptr, ConnectionType::kEthernet);
   TestWithServiceType(shill::kTypeWifi, nullptr, ConnectionType::kWifi);
@@ -203,6 +218,10 @@
   TestWithServiceType("foo", nullptr, ConnectionType::kUnknown);
 }
 
+TEST_F(ConnectionManagerTest, DisconnectTest) {
+  TestWithServiceDisconnected(ConnectionType::kDisconnected);
+}
+
 TEST_F(ConnectionManagerTest, AllowUpdatesOverEthernetTest) {
   // Updates over Ethernet are allowed even if there's no policy.
   EXPECT_TRUE(cmut_.IsUpdateAllowedOver(ConnectionType::kEthernet,
diff --git a/connection_utils.cc b/connection_utils.cc
index 9b6b526..aeb0163 100644
--- a/connection_utils.cc
+++ b/connection_utils.cc
@@ -18,6 +18,12 @@
 
 #include <shill/dbus-constants.h>
 
+namespace {
+// Not defined by shill since we don't use this outside of UE.
+constexpr char kTypeDisconnected[] = "Disconnected";
+constexpr char kTypeUnknown[] = "Unknown";
+}  // namespace
+
 namespace chromeos_update_engine {
 namespace connection_utils {
 
@@ -32,6 +38,8 @@
     return ConnectionType::kBluetooth;
   } else if (type_str == shill::kTypeCellular) {
     return ConnectionType::kCellular;
+  } else if (type_str == kTypeDisconnected) {
+    return ConnectionType::kDisconnected;
   }
   return ConnectionType::kUnknown;
 }
@@ -59,10 +67,12 @@
       return shill::kTypeBluetooth;
     case ConnectionType::kCellular:
       return shill::kTypeCellular;
+    case ConnectionType::kDisconnected:
+      return kTypeDisconnected;
     case ConnectionType::kUnknown:
-      return "Unknown";
+      return kTypeUnknown;
   }
-  return "Unknown";
+  return kTypeUnknown;
 }
 
 }  // namespace connection_utils
diff --git a/connection_utils.h b/connection_utils.h
index e385517..d5133a1 100644
--- a/connection_utils.h
+++ b/connection_utils.h
@@ -22,6 +22,7 @@
 namespace chromeos_update_engine {
 
 enum class ConnectionType {
+  kDisconnected,
   kEthernet,
   kWifi,
   kWimax,
diff --git a/metrics_constants.h b/metrics_constants.h
index abec2ad..eabb8fb 100644
--- a/metrics_constants.h
+++ b/metrics_constants.h
@@ -107,14 +107,15 @@
 //
 // This is used in the UpdateEngine.Attempt.ConnectionType histogram.
 enum class ConnectionType {
-  kUnknown,           // Unknown.
-  kEthernet,          // Ethernet.
-  kWifi,              // Wireless.
-  kWimax,             // WiMax.
-  kBluetooth,         // Bluetooth.
-  kCellular,          // Cellular.
-  kTetheredEthernet,  // Tethered (Ethernet).
-  kTetheredWifi,      // Tethered (Wifi).
+  kUnknown = 0,           // Unknown.
+  kEthernet = 1,          // Ethernet.
+  kWifi = 2,              // Wireless.
+  kWimax = 3,             // WiMax.
+  kBluetooth = 4,         // Bluetooth.
+  kCellular = 5,          // Cellular.
+  kTetheredEthernet = 6,  // Tethered (Ethernet).
+  kTetheredWifi = 7,      // Tethered (Wifi).
+  kDisconnected = 8,      // Disconnected.
 
   kNumConstants,
   kUnset = -1
diff --git a/metrics_utils.cc b/metrics_utils.cc
index b85f257..018f2e4 100644
--- a/metrics_utils.cc
+++ b/metrics_utils.cc
@@ -247,6 +247,9 @@
     case ConnectionType::kUnknown:
       return metrics::ConnectionType::kUnknown;
 
+    case ConnectionType::kDisconnected:
+      return metrics::ConnectionType::kDisconnected;
+
     case ConnectionType::kEthernet:
       if (tethering == ConnectionTethering::kConfirmed)
         return metrics::ConnectionType::kTetheredEthernet;
diff --git a/metrics_utils_unittest.cc b/metrics_utils_unittest.cc
index edf6bc3..417a72b 100644
--- a/metrics_utils_unittest.cc
+++ b/metrics_utils_unittest.cc
@@ -32,6 +32,9 @@
   EXPECT_EQ(metrics::ConnectionType::kUnknown,
             GetConnectionType(ConnectionType::kUnknown,
                               ConnectionTethering::kUnknown));
+  EXPECT_EQ(metrics::ConnectionType::kDisconnected,
+            GetConnectionType(ConnectionType::kDisconnected,
+                              ConnectionTethering::kUnknown));
   EXPECT_EQ(metrics::ConnectionType::kEthernet,
             GetConnectionType(ConnectionType::kEthernet,
                               ConnectionTethering::kUnknown));
diff --git a/update_manager/boxed_value_unittest.cc b/update_manager/boxed_value_unittest.cc
index 99d578c..212db36 100644
--- a/update_manager/boxed_value_unittest.cc
+++ b/update_manager/boxed_value_unittest.cc
@@ -161,6 +161,9 @@
 }
 
 TEST(UmBoxedValueTest, ConnectionTypeToString) {
+  EXPECT_EQ(
+      "Disconnected",
+      BoxedValue(new ConnectionType(ConnectionType::kDisconnected)).ToString());
   EXPECT_EQ("ethernet",
             BoxedValue(new ConnectionType(ConnectionType::kEthernet))
             .ToString());