diff --git a/drivers/server/src/main/java/org/onosproject/drivers/server/BasicServerDriver.java b/drivers/server/src/main/java/org/onosproject/drivers/server/BasicServerDriver.java
index 046578a..4fffe6e 100644
--- a/drivers/server/src/main/java/org/onosproject/drivers/server/BasicServerDriver.java
+++ b/drivers/server/src/main/java/org/onosproject/drivers/server/BasicServerDriver.java
@@ -21,8 +21,7 @@
 import org.onosproject.net.driver.AbstractHandlerBehaviour;
 import org.onosproject.net.driver.DriverHandler;
 import org.onosproject.protocol.rest.RestSBController;
-
-import org.onlab.osgi.ServiceNotFoundException;
+import org.onosproject.protocol.rest.RestSBDevice;
 
 import org.slf4j.Logger;
 
@@ -47,7 +46,8 @@
      */
     public    static final MediaType  JSON = MediaType.valueOf(MediaType.APPLICATION_JSON);
     protected static final String ROOT_URL = "";
-    public    static final String BASE_URL = ROOT_URL + "/metron";
+    protected static final String SLASH = "/";
+    public    static final String BASE_URL = ROOT_URL + SLASH + "metron";
 
     /**
      * Common parameters to be exchanged with the server's agent.
@@ -85,61 +85,36 @@
     public BasicServerDriver() {};
 
     /**
-     * Initialize the REST SB controller (if not already).
-     * Creates a handler and a controller only once, and
-     * then re-uses these objects.
+     * Retrieve an instance of the driver handler.
      *
-     * @throws ServiceNotFoundException when either the handler
-     *         or the controller cannot be retrieved.
+     * @return DriverHandler instance
      */
-    private void init() {
+    protected DriverHandler getHandler() {
         synchronized (CONTROLLER_LOCK) {
-            // Already done
-            if ((handler != null) && (controller != null)) {
-                return;
-            }
-
             handler = handler();
             checkNotNull(handler, HANDLER_NULL);
-            controller = handler.get(RestSBController.class);
-            checkNotNull(controller, CONTROLLER_NULL);
         }
+
+        return handler;
     }
 
     /**
      * Retrieve an instance of the REST SB controller.
-     * Method init will only be called the first time
-     * this method (or getHandler) is invoked.
      *
      * @return RestSBController instance
      */
     public RestSBController getController() {
         synchronized (CONTROLLER_LOCK) {
             if (controller == null) {
-                init();
+                controller = getHandler().get(RestSBController.class);
+                checkNotNull(controller, CONTROLLER_NULL);
             }
         }
+
         return controller;
     }
 
     /**
-     * Retrieve an instance of the driver handler.
-     * Method init will only be called the first time
-     * this method (or getController) is invoked.
-     *
-     * @return DriverHandler instance
-     */
-    protected DriverHandler getHandler() {
-        synchronized (CONTROLLER_LOCK) {
-            if (handler == null) {
-                init();
-            }
-        }
-
-        return handler;
-    }
-
-    /**
      * Finds the NIC name that corresponds to a device's port number.
      *
      * @param deviceId a device ID
@@ -147,6 +122,10 @@
      * @return device's NIC name
      */
     public static String findNicInterfaceWithPort(DeviceId deviceId, long port) {
+        if (controller == null) {
+            return null;
+        }
+
         RestServerSBDevice device = null;
         try {
             device = (RestServerSBDevice) controller.getDevice(deviceId);
@@ -165,8 +144,7 @@
      * @param enumType the enum class to get its types
      * @return String with all enumeration types
      */
-    public static <E extends Enum<E>> String enumTypesToString(
-            Class<E> enumType) {
+    public static <E extends Enum<E>> String enumTypesToString(Class<E> enumType) {
         String allTypes = "";
         for (E en : EnumSet.allOf(enumType)) {
             allTypes += en.toString() + " ";
@@ -215,4 +193,21 @@
         return false;
     }
 
+    /**
+     * Upon a failure to contact a device, the driver
+     * raises a disconnect event by resetting the
+     * activity flag of this device.
+     *
+     * @param device a device to disconnect
+     */
+    protected void raiseDeviceDisconnect(RestSBDevice device) {
+        // Already done!
+        if (!device.isActive()) {
+            return;
+        }
+
+        log.info("Setting device {} inactive", device.deviceId());
+        device.setActive(false);
+    }
+
 }
diff --git a/drivers/server/src/main/java/org/onosproject/drivers/server/FlowRuleProgrammableServerImpl.java b/drivers/server/src/main/java/org/onosproject/drivers/server/FlowRuleProgrammableServerImpl.java
index efc7bd6..9c38fe8 100644
--- a/drivers/server/src/main/java/org/onosproject/drivers/server/FlowRuleProgrammableServerImpl.java
+++ b/drivers/server/src/main/java/org/onosproject/drivers/server/FlowRuleProgrammableServerImpl.java
@@ -62,7 +62,7 @@
     /**
      * Resource endpoints of the server agent (REST server-side).
      */
-    private static final String RULE_MANAGEMENT_URL = BASE_URL + "/rules";
+    private static final String RULE_MANAGEMENT_URL = BASE_URL + SLASH + "rules";
 
     /**
      * Parameters to be exchanged with the server's agent.
@@ -360,19 +360,23 @@
      * @return boolean removal status
      */
     private boolean removeNicFlowRule(DeviceId deviceId, long ruleId) {
-        // Remove rule with ID from this server
-        int response = getController().delete(deviceId,
-            RULE_MANAGEMENT_URL + "/" + Long.toString(ruleId), null, JSON);
+        int response = -1;
 
-        if (!checkStatusCode(response)) {
-            log.error("Failed to remove flow rule {} from device {}",
-                ruleId, deviceId);
+        // Try to remove the rule, although server might be unreachable
+        try {
+            response = getController().delete(deviceId,
+                RULE_MANAGEMENT_URL + SLASH + Long.toString(ruleId), null, JSON);
+        } catch (Exception ex) {
+            log.error("Failed to remove flow rule {} from device {}", ruleId, deviceId);
             return false;
         }
 
-        log.info("Successfully removed flow rule {} from device {}",
-            ruleId, deviceId);
+        if (!checkStatusCode(response)) {
+            log.error("Failed to remove flow rule {} from device {}", ruleId, deviceId);
+            return false;
+        }
 
+        log.info("Successfully removed flow rule {} from device {}", ruleId, deviceId);
         return true;
     }
 
diff --git a/drivers/server/src/main/java/org/onosproject/drivers/server/ServerControllerConfig.java b/drivers/server/src/main/java/org/onosproject/drivers/server/ServerControllerConfig.java
index db62a6b..3ffbc91 100644
--- a/drivers/server/src/main/java/org/onosproject/drivers/server/ServerControllerConfig.java
+++ b/drivers/server/src/main/java/org/onosproject/drivers/server/ServerControllerConfig.java
@@ -53,7 +53,7 @@
     /**
      * Resource endpoints of the server agent (REST server-side).
      */
-    private static final String CONTROLLERS_CONF_URL = BASE_URL + "/controllers";
+    private static final String CONTROLLERS_CONF_URL = BASE_URL + SLASH + "controllers";
 
     /**
      * Parameters to be exchanged with the server's agent.
@@ -219,7 +219,7 @@
             log.info("Remove controller with {}:{}:{}",
                 ctrl.type(), ctrl.ip().toString(), ctrl.port());
 
-            String remCtrlUrl = CONTROLLERS_CONF_URL + "/" + ctrl.ip().toString();
+            String remCtrlUrl = CONTROLLERS_CONF_URL + SLASH + ctrl.ip().toString();
 
             // Remove this controller
             int response = getController().delete(deviceId, remCtrlUrl, null, JSON);
diff --git a/drivers/server/src/main/java/org/onosproject/drivers/server/ServerDevicesDiscovery.java b/drivers/server/src/main/java/org/onosproject/drivers/server/ServerDevicesDiscovery.java
index 0755bcd..10203a3 100644
--- a/drivers/server/src/main/java/org/onosproject/drivers/server/ServerDevicesDiscovery.java
+++ b/drivers/server/src/main/java/org/onosproject/drivers/server/ServerDevicesDiscovery.java
@@ -99,9 +99,9 @@
     /**
      * Resource endpoints of the server agent (REST server-side).
      */
-    private static final String RESOURCE_DISCOVERY_URL   = BASE_URL + "/resources";
-    private static final String GLOBAL_STATS_URL         = BASE_URL + "/stats";
-    private static final String SERVICE_CHAINS_STATS_URL = BASE_URL + "/chains_stats";  // + /ID
+    private static final String RESOURCE_DISCOVERY_URL   = BASE_URL + SLASH + "resources";
+    private static final String GLOBAL_STATS_URL         = BASE_URL + SLASH + "stats";
+    private static final String SERVICE_CHAINS_STATS_URL = BASE_URL + SLASH + "chains_stats";  // + /ID
 
     /**
      * Parameters to be exchanged with the server's agent.
@@ -211,9 +211,6 @@
      * @return a DeviceDescription with the device's features
      */
     private DeviceDescription getDeviceDetails(DeviceId deviceId) {
-        // Create a description for this server device
-        ServerDeviceDescription desc = null;
-
         // Retrieve the device ID, if null given
         if (deviceId == null) {
             deviceId = getHandler().data().deviceId();
@@ -230,7 +227,7 @@
             response = getController().get(deviceId, RESOURCE_DISCOVERY_URL, JSON);
         } catch (ProcessingException pEx) {
             log.error("Failed to discover the device details of: {}", deviceId);
-            return desc;
+            return null;
         }
 
         // Load the JSON into objects
@@ -244,12 +241,12 @@
             objNode = (ObjectNode) jsonNode;
         } catch (IOException ioEx) {
             log.error("Failed to discover the device details of: {}", deviceId);
-            return desc;
+            return null;
         }
 
         if (jsonMap == null) {
             log.error("Failed to discover the device details of: {}", deviceId);
-            return desc;
+            return null;
         }
 
         // Get all the attributes
@@ -357,6 +354,9 @@
         getController().removeDevice(deviceId);
         getController().addDevice((RestSBDevice) dev);
 
+        // Create a description for this server device
+        ServerDeviceDescription desc = null;
+
         try {
             desc = new DefaultServerDeviceDescription(
                 new URI(id), Device.Type.SERVER, vendor,
@@ -376,44 +376,31 @@
 
     @Override
     public List<PortDescription> discoverPortDetails() {
-        // List of port descriptions to return
-        List<PortDescription> portDescriptions = Lists.newArrayList();
-
         // Retrieve the device ID
         DeviceId deviceId = getHandler().data().deviceId();
         checkNotNull(deviceId, DEVICE_ID_NULL);
+
         // .. and object
         RestServerSBDevice device = null;
-
-        // In case this method is called before discoverDeviceDetails,
-        // there is missing information to be gathered.
-        short i = 0;
-        while ((device == null) && (i < DISCOVERY_RETRIES)) {
-            i++;
-
-            try {
-                device = (RestServerSBDevice) getController().getDevice(deviceId);
-            } catch (ClassCastException ccEx) {
-                try {
-                    Thread.sleep(1);
-                } catch (InterruptedException intEx) {
-                    // Just retry
-                    continue;
-                }
-            }
-
-            // No device
-            if (device == null) {
-                // This method will add the device to the RestSBController
-                this.getDeviceDetails(deviceId);
-            }
+        try {
+            device = (RestServerSBDevice) getController().getDevice(deviceId);
+        } catch (ClassCastException ccEx) {
+            log.error("Failed to discover ports for device {}", deviceId);
+            return Collections.EMPTY_LIST;
         }
 
-        if ((device == null) || (device.nics() == null)) {
+        if (device == null) {
+            log.error("No device with ID {} is available for port discovery", deviceId);
+            return Collections.EMPTY_LIST;
+        }
+        if ((device.nics() == null) || (device.nics().size() == 0)) {
             log.error("No ports available on {}", deviceId);
             return Collections.EMPTY_LIST;
         }
 
+        // List of port descriptions to return
+        List<PortDescription> portDescriptions = Lists.newArrayList();
+
         // Sorted list of NIC ports
         Set<NicDevice> nics = new TreeSet(device.nics());
 
@@ -537,7 +524,9 @@
                 deviceId);
             return monStats;
         }
-        checkNotNull(device, DEVICE_NULL);
+        if ((device == null) || (!device.isActive())) {
+            return monStats;
+        }
 
         // Hit the path that provides the server's global resources
         InputStream response = null;
@@ -546,6 +535,7 @@
         } catch (ProcessingException pEx) {
             log.error("Failed to retrieve global monitoring statistics from device {}",
                 deviceId);
+            raiseDeviceDisconnect(device);
             return monStats;
         }
 
@@ -560,12 +550,14 @@
         } catch (IOException ioEx) {
             log.error("Failed to retrieve global monitoring statistics from device {}",
                 deviceId);
+            raiseDeviceDisconnect(device);
             return monStats;
         }
 
         if (jsonMap == null) {
             log.error("Failed to retrieve global monitoring statistics from device {}",
                 deviceId);
+            raiseDeviceDisconnect(device);
             return monStats;
         }
 
@@ -629,10 +621,12 @@
                 deviceId);
             return monStats;
         }
-        checkNotNull(device, DEVICE_NULL);
+        if (device == null) {
+            return monStats;
+        }
 
         // Create a resource-specific URL
-        String scUrl = SERVICE_CHAINS_STATS_URL + "/" + tcId.toString();
+        String scUrl = SERVICE_CHAINS_STATS_URL + SLASH + tcId.toString();
 
         // Hit the path that provides the server's specific resources
         InputStream response = null;
@@ -641,6 +635,7 @@
         } catch (ProcessingException pEx) {
             log.error("Failed to retrieve monitoring statistics from device {}",
                 deviceId);
+            raiseDeviceDisconnect(device);
             return monStats;
         }
 
@@ -656,12 +651,14 @@
         } catch (IOException ioEx) {
             log.error("Failed to retrieve monitoring statistics from device {}",
                 deviceId);
+            raiseDeviceDisconnect(device);
             return monStats;
         }
 
         if (jsonMap == null) {
             log.error("Failed to retrieve monitoring statistics from device {}",
                 deviceId);
+            raiseDeviceDisconnect(device);
             return monStats;
         }
 
@@ -711,9 +708,8 @@
      * @param objNode input JSON node with CPU statistics information
      * @return list of (per core) CpuStatistics
      */
-    private Collection<CpuStatistics> parseCpuStatistics(
-            DeviceId deviceId, JsonNode objNode) {
-        if (objNode == null) {
+    private Collection<CpuStatistics> parseCpuStatistics(DeviceId deviceId, JsonNode objNode) {
+        if ((deviceId == null) || (objNode == null)) {
             return Collections.EMPTY_LIST;
         }
 
@@ -755,9 +751,8 @@
      * @param objNode input JSON node with NIC statistics information
      * @return list of (per port) PortStatistics
      */
-    private Collection<PortStatistics> parseNicStatistics(
-            DeviceId deviceId, JsonNode objNode) {
-        if (objNode == null) {
+    private Collection<PortStatistics> parseNicStatistics(DeviceId deviceId, JsonNode objNode) {
+        if ((deviceId == null) || (objNode == null)) {
             return Collections.EMPTY_LIST;
         }
 
@@ -767,7 +762,9 @@
         } catch (ClassCastException ccEx) {
             return Collections.EMPTY_LIST;
         }
-        checkNotNull(device, DEVICE_NULL);
+        if (device == null) {
+            return Collections.EMPTY_LIST;
+        }
 
         Collection<PortStatistics> nicStats = Lists.newArrayList();