diff --git a/hal.conf.example b/hal.conf.example
index 919a078a..76e4ee75 100755
--- a/hal.conf.example
+++ b/hal.conf.example
@@ -5,5 +5,5 @@ sync_port=6666
 #tellstick.com_port=COM5
 #nutups.host=
 #nutups.port=
-# Network scanning is disabled by default as it is not appropriate for all networks
-#netscan.scanip=true
\ No newline at end of file
+# Network scanning should probably be disabled in some networks (default on)
+#netscan.ipscan=false
\ No newline at end of file
diff --git a/src/se/hal/HalContext.java b/src/se/hal/HalContext.java
index b4bc41e7..15b012d6 100755
--- a/src/se/hal/HalContext.java
+++ b/src/se/hal/HalContext.java
@@ -182,6 +182,12 @@ public class HalContext {
     public static int getIntegerProperty(String key){
         return Integer.parseInt(getStringProperty(key));
     }
+    public static boolean getBooleanProperty(String key) {
+        return Boolean.parseBoolean(getStringProperty(key));
+    }
+    public static boolean containsProperty(String key) {
+        return getStringProperty(key) != null;
+    }
     public static void setProperty(String key, String value) throws SQLException {
         PreparedStatement stmt = db.getPreparedStatement("REPLACE INTO conf (key, value) VALUES (?, ?)");
         stmt.setObject(1, key);
@@ -190,6 +196,9 @@ public class HalContext {
         dbConf.setProperty(key, value);
     }
 
+
+
+
     public static DBConnection getDB(){
         return db;
     }
@@ -202,4 +211,5 @@ public class HalContext {
     	HalContext.db = db;
     }
 
+
 }
diff --git a/src/se/hal/plugin/netscan/NetScanController.java b/src/se/hal/plugin/netscan/NetScanController.java
index 6ec30e4a..c8d2b9ad 100755
--- a/src/se/hal/plugin/netscan/NetScanController.java
+++ b/src/se/hal/plugin/netscan/NetScanController.java
@@ -1,7 +1,9 @@
 package se.hal.plugin.netscan;
 
+import se.hal.HalContext;
 import se.hal.intf.*;
 import se.hal.struct.devicedata.SwitchEventData;
+import zutil.InetUtil;
 import zutil.log.LogUtil;
 import zutil.net.InetScanner;
 import zutil.net.InetScanner.InetScanListener;
@@ -9,9 +11,10 @@ import zutil.osal.MultiCommandExecutor;
 
 import java.io.IOException;
 import java.net.InetAddress;
-import java.net.NetworkInterface;
-import java.net.SocketException;
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
@@ -24,47 +27,54 @@ public class NetScanController implements HalEventController, HalAutoScannableCo
     public static Logger logger = LogUtil.getLogger();
     private static final int NETWORK_SYNC_INTERVAL = 3 * 60 * 60 * 1000; // 3 hours
     private static final int PING_INTERVAL = 10 * 1000; // 10 sec
+    private static final String PARAM_IPSCAN = "netscan.ipscan";
 
     private ScheduledExecutorService executor;
     private HalEventReportListener listener;
-    private ArrayList<LocalNetworkDevice> devices = new ArrayList<>();
+    /** A register and a cache of previous state **/
+    private HashMap<LocalNetworkDevice,SwitchEventData> devices = new HashMap<>();
 
 
 
     @Override
     public boolean isAvailable() {
-        return ! InetScanner.getLocalInet4Address().isEmpty();
+        return ! InetUtil.getLocalInet4Address().isEmpty();
     }
 
     @Override
     public void initialize() throws Exception {
         executor = Executors.newScheduledThreadPool(1);
-        executor.scheduleAtFixedRate(new Runnable() {
-            @Override
-            public void run() {
-                try {
-                    logger.fine("Starting network scan...");
-                    InetScanner scanner = new InetScanner();
-                    scanner.setListener(NetScanController.this);
-                    scanner.scan(InetScanner.getLocalInet4Address().get(0));
-                    logger.fine("Network scan done");
-                } catch (Exception e) {
-                    e.printStackTrace();
+        executor.scheduleAtFixedRate(NetScanController.this, 10_000, PING_INTERVAL, TimeUnit.MILLISECONDS);
+        if (!HalContext.containsProperty(PARAM_IPSCAN) || HalContext.getBooleanProperty(PARAM_IPSCAN)) {
+            executor.scheduleAtFixedRate(new Runnable() {
+                @Override
+                public void run() {
+                    try {
+                        logger.fine("Starting network scan...");
+                        InetScanner scanner = new InetScanner();
+                        scanner.setListener(NetScanController.this);
+                        scanner.scan(InetUtil.getLocalInet4Address().get(0));
+                        logger.fine("Network scan done");
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
                 }
-            }
-        }, 30_000, NETWORK_SYNC_INTERVAL, TimeUnit.MILLISECONDS);
-        executor.scheduleAtFixedRate(NetScanController.this, 10_001, PING_INTERVAL, TimeUnit.MILLISECONDS);
+            }, 30_000, NETWORK_SYNC_INTERVAL, TimeUnit.MILLISECONDS);
+        }
     }
 
     @Override
     public void run() {
         try(MultiCommandExecutor executor = new MultiCommandExecutor();){
-            for (int i = 0; i < devices.size(); i++) {
-                LocalNetworkDevice device = devices.get(i);
+            for (Map.Entry<LocalNetworkDevice,SwitchEventData> entry : devices.entrySet()) {
                 if (listener != null) {
-                    logger.fine("Pinging ip: "+device.getHost());
-                    boolean online = InetScanner.isReachable(device.getHost(), executor);
-                    listener.reportReceived(device, new SwitchEventData(online, System.currentTimeMillis()));
+                    boolean online = InetScanner.isReachable(entry.getKey().getHost(), executor);
+                    if (entry.getValue() == null || entry.getValue().isOn() == online) {
+                        entry.setValue(
+                                new SwitchEventData(online, System.currentTimeMillis()));
+                        logger.fine("IP "+entry.getKey().getHost() +" state has changed to "+ entry.getValue());
+                        listener.reportReceived(entry.getKey(), entry.getValue());
+                    }
                 }
             }
         } catch (IOException e) {
@@ -85,7 +95,7 @@ public class NetScanController implements HalEventController, HalAutoScannableCo
     @Override
     public void register(HalEventConfig event) {
         if (event instanceof LocalNetworkDevice)
-            devices.add((LocalNetworkDevice) event);
+            devices.put((LocalNetworkDevice) event, null);
     }
     @Override
     public void deregister(HalEventConfig event) {