diff --git a/src/arduino_platform.h b/src/arduino_platform.h
index 3b44101..82432a9 100644
--- a/src/arduino_platform.h
+++ b/src/arduino_platform.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include "knx/platform.h"
 
 #include "Arduino.h"
diff --git a/src/esp32_platform.cpp b/src/esp32_platform.cpp
index d3e0620..70fc9c0 100644
--- a/src/esp32_platform.cpp
+++ b/src/esp32_platform.cpp
@@ -8,6 +8,15 @@
 
 #ifndef KNX_SERIAL
     #define KNX_SERIAL Serial1
+    #pragma warn "KNX_SERIAL not defined, using Serial1"
+#endif
+ 
+#ifdef KNX_IP_LAN
+    #include "ETH.h"
+    #define KNX_NETIF ETH
+#else // KNX_IP_WIFI
+    #include <WiFi.h>
+    #define KNX_NETIF WiFi
 #endif
 
 Esp32Platform::Esp32Platform()
@@ -44,22 +53,22 @@ void Esp32Platform::setupUart()
 
 uint32_t Esp32Platform::currentIpAddress()
 {
-    return WiFi.localIP();
+    return KNX_NETIF.localIP();
 }
 
 uint32_t Esp32Platform::currentSubnetMask()
 {
-    return WiFi.subnetMask();
+    return KNX_NETIF.subnetMask();
 }
 
 uint32_t Esp32Platform::currentDefaultGateway()
 {
-    return WiFi.gatewayIP();
+    return KNX_NETIF.gatewayIP();
 }
 
 void Esp32Platform::macAddress(uint8_t* addr)
 {
-    esp_wifi_get_mac(WIFI_IF_STA, addr);
+    KNX_NETIF.macAddress(addr);
 }
 
 uint32_t Esp32Platform::uniqueSerialNumber()
@@ -81,7 +90,7 @@ void Esp32Platform::setupMultiCast(uint32_t addr, uint16_t port)
     IPAddress mcastaddr(htonl(addr));
 
     KNX_DEBUG_SERIAL.printf("setup multicast addr: %s port: %d ip: %s\n", mcastaddr.toString().c_str(), port,
-                            WiFi.localIP().toString().c_str());
+        KNX_NETIF.localIP().toString().c_str());
     uint8_t result = _udp.beginMulticast(mcastaddr, port);
     KNX_DEBUG_SERIAL.printf("result %d\n", result);
 }
diff --git a/src/esp32_platform.h b/src/esp32_platform.h
index 4f8fb8f..3ace355 100644
--- a/src/esp32_platform.h
+++ b/src/esp32_platform.h
@@ -1,9 +1,10 @@
 #ifdef ARDUINO_ARCH_ESP32
 #include "arduino_platform.h"
-#include <WiFi.h>
-#include <WiFiUdp.h>
 
 
+
+#include <WiFiUdp.h>
+
 class Esp32Platform : public ArduinoPlatform
 {
     public:
diff --git a/src/knx/bau091A.cpp b/src/knx/bau091A.cpp
index 331cbbe..d468ef7 100644
--- a/src/knx/bau091A.cpp
+++ b/src/knx/bau091A.cpp
@@ -188,19 +188,25 @@ TPAckType Bau091A::isAckRequired(uint16_t address, bool isGrpAddr)
     {
         // ACK for broadcasts
         if (address == 0)
+        {
             ack = TPAckType::AckReqAck;
-
-        if (lcconfig & LCCONFIG::GROUP_IACK_ROUT)
-
-            // is group address in filter table? ACK if yes, No if not
-            if (_netLayer.isRoutedGroupAddress(address, 1))
-                ack = TPAckType::AckReqAck;
-            else
-                ack = TPAckType::AckReqNone;
+        }
         else
-            // all are ACKED
-            ack = TPAckType::AckReqAck;
-
+        {
+            if(lcconfig & LCCONFIG::GROUP_IACK_ROUT)
+            {
+                // is group address in filter table? ACK if yes, No if not
+                if(_netLayer.isRoutedGroupAddress(address, 1))
+                    ack = TPAckType::AckReqAck;
+                else
+                    ack = TPAckType::AckReqNone;
+            }
+            else
+            {
+                // all are ACKED
+                ack = TPAckType::AckReqAck;
+            }
+        }
 #ifdef KNX_TUNNELING
 
         if (_dlLayerPrimary.isSentToTunnel(address, isGrpAddr))
@@ -226,7 +232,6 @@ TPAckType Bau091A::isAckRequired(uint16_t address, bool isGrpAddr)
 
 #endif
     }
-
     return ack;
 }
 
diff --git a/src/knx/device_object.h b/src/knx/device_object.h
index 8bfd2d2..fb3fd74 100644
--- a/src/knx/device_object.h
+++ b/src/knx/device_object.h
@@ -6,15 +6,15 @@
 
 class DeviceObject: public InterfaceObject
 {
-    public:
-        // increase this version anytime DeviceObject-API changes
-        // the following value represents the serialized representation of DeviceObject.
-        const uint16_t apiVersion = 1;
-
-        DeviceObject();
-        uint8_t* save(uint8_t* buffer) override;
-        const uint8_t* restore(const uint8_t* buffer) override;
-        uint16_t saveSize() override;
+public:
+    // increase this version anytime DeviceObject-API changes 
+    // the following value represents the serialized representation of DeviceObject.
+    const uint16_t apiVersion = 2;
+    
+    DeviceObject();
+    uint8_t* save(uint8_t* buffer) override;
+    const uint8_t* restore(const uint8_t* buffer) override;
+    uint16_t saveSize() override;
 
         uint16_t individualAddress();
         void individualAddress(uint16_t value);
diff --git a/src/knx/group_object.cpp b/src/knx/group_object.cpp
index dcec322..a37fa1f 100644
--- a/src/knx/group_object.cpp
+++ b/src/knx/group_object.cpp
@@ -312,6 +312,7 @@ bool GroupObject::valueNoSend(const KNXValue& value, const Dpt& type)
         commFlag(Ok);
 
     return encodingDone;
+    return encodingDone;
 }
 
 bool GroupObject::valueNoSendCompare(const KNXValue& value, const Dpt& type)
diff --git a/src/knx/ip_data_link_layer.cpp b/src/knx/ip_data_link_layer.cpp
index 5f853b7..461350c 100644
--- a/src/knx/ip_data_link_layer.cpp
+++ b/src/knx/ip_data_link_layer.cpp
@@ -504,9 +504,8 @@ void IpDataLinkLayer::loopHandleSearchRequestExtended(uint8_t* buffer, uint16_t
 
     if (searchRequest.srpRequestDIBs)
     {
-        println("srpRequestDIBs");
-
-        if (searchRequest.requestedDIB(IP_CONFIG))
+        //println("srpRequestDIBs");
+        if(searchRequest.requestedDIB(IP_CONFIG))
             dibLength += LEN_IP_CONFIG_DIB; //16
 
         if (searchRequest.requestedDIB(IP_CUR_CONFIG))
@@ -556,9 +555,9 @@ void IpDataLinkLayer::loopHandleSearchRequestExtended(uint8_t* buffer, uint16_t
             searchResponse.setTunnelingInfo(_ipParameters, _deviceObject, tunnels);
     }
 
-    if (searchResponse.totalLength() > 150)
+    if(searchResponse.totalLength() > 500)
     {
-        println("skipped response cause length is not plausible");
+        printf("skipped response length > 500. Length: %d bytes\n", searchResponse.totalLength());
         return;
     }
 
@@ -715,8 +714,7 @@ void IpDataLinkLayer::loopHandleConnectRequest(uint8_t* buffer, uint16_t length,
             tunnelResOptions[i] = (*(tunCtrlBytes + i) & 0x60) >> 5;
         }
 
-
-        if (tunnelResActive[i])  // tunnel reserve feature active for this tunnel
+        if(resTunActive && tunnelResActive[i])   // tunnel reserve feature active for this tunnel
         {
 #ifdef KNX_LOG_TUNNELING
             print("tunnel reserve feature active for this tunnel: ");
@@ -834,8 +832,9 @@ void IpDataLinkLayer::loopHandleConnectRequest(uint8_t* buffer, uint16_t length,
                 tun = nullptr;
                 break;
             }
+        if(tun)
+            tun->IndividualAddress = tunPa;
 
-        tun->IndividualAddress = tunPa;
     }
 
     if (tun == nullptr)
@@ -869,8 +868,8 @@ void IpDataLinkLayer::loopHandleConnectRequest(uint8_t* buffer, uint16_t length,
         _lastChannelId = 0;
 
     tun->IpAddress = srcIP;
-    tun->PortData = srcPort;
-    tun->PortCtrl = connRequest.hpaiCtrl().ipPortNumber() ? connRequest.hpaiCtrl().ipPortNumber() : srcPort;
+    tun->PortData = connRequest.hpaiData().ipPortNumber()?connRequest.hpaiData().ipPortNumber():srcPort;
+    tun->PortCtrl = connRequest.hpaiCtrl().ipPortNumber()?connRequest.hpaiCtrl().ipPortNumber():srcPort;
 
     print("New Tunnel-Connection[");
     print(tunIdx);
diff --git a/src/knx/ip_data_link_layer.h b/src/knx/ip_data_link_layer.h
index 56827ca..d8e7227 100644
--- a/src/knx/ip_data_link_layer.h
+++ b/src/knx/ip_data_link_layer.h
@@ -52,8 +52,8 @@ class IpDataLinkLayer : public DataLinkLayer
         IpParameterObject& _ipParameters;
         DataLinkLayerCallbacks* _dllcb;
 #ifdef KNX_TUNNELING
-        KnxIpTunnelConnection tunnels[KNX_TUNNELING];
-        uint8_t _lastChannelId = 1;
+    KnxIpTunnelConnection tunnels[KNX_TUNNELING];
+    uint8_t _lastChannelId = 0;
 #endif
 };
 #endif
\ No newline at end of file
diff --git a/src/knx/knx_ip_connect_response.cpp b/src/knx/knx_ip_connect_response.cpp
index 2706341..0d59293 100644
--- a/src/knx/knx_ip_connect_response.cpp
+++ b/src/knx/knx_ip_connect_response.cpp
@@ -17,7 +17,8 @@ KnxIpConnectResponse::KnxIpConnectResponse(IpParameterObject& parameters, uint16
 
     _crd.length((type == 4) ? 4 : 2); //TunnelConnectionResponse length = 4; ConfigConnectionResponse length = 2;
     _crd.type(type);
-    _crd.address(address);
+    if(type == 4) // only fill address when it is a TunnelConnectionResponse
+        _crd.address(address);
 }
 
 KnxIpConnectResponse::KnxIpConnectResponse(uint8_t channel, uint8_t errorCode)
diff --git a/src/knx/knx_ip_search_response_extended.cpp b/src/knx/knx_ip_search_response_extended.cpp
index c624532..1bd2acd 100644
--- a/src/knx/knx_ip_search_response_extended.cpp
+++ b/src/knx/knx_ip_search_response_extended.cpp
@@ -34,7 +34,7 @@ KnxIpSearchResponseExtended::KnxIpSearchResponseExtended(IpParameterObject& para
 
 void KnxIpSearchResponseExtended::setDeviceInfo(IpParameterObject& parameters, DeviceObject& deviceObject)
 {
-    println("setDeviceInfo");
+    //setDeviceInfo");
     KnxIpDeviceInformationDIB _deviceInfo(_data + currentPos);
     _deviceInfo.length(LEN_DEVICE_INFORMATION_DIB);
     _deviceInfo.code(DEVICE_INFO);
@@ -65,7 +65,7 @@ void KnxIpSearchResponseExtended::setDeviceInfo(IpParameterObject& parameters, D
 
 void KnxIpSearchResponseExtended::setSupportedServices()
 {
-    println("setSupportedServices");
+    //println("setSupportedServices");
     KnxIpSupportedServiceDIB _supportedServices(_data + currentPos);
     _supportedServices.length(LEN_SERVICE_DIB);
     _supportedServices.code(SUPP_SVC_FAMILIES);
@@ -82,7 +82,7 @@ void KnxIpSearchResponseExtended::setSupportedServices()
 
 void KnxIpSearchResponseExtended::setIpConfig(IpParameterObject& parameters)
 {
-    println("setIpConfig");
+    //println("setIpConfig");
     KnxIpConfigDIB _ipConfig(_data + currentPos);
     _ipConfig.length(LEN_IP_CONFIG_DIB);
     _ipConfig.code(IP_CONFIG);
@@ -97,14 +97,14 @@ void KnxIpSearchResponseExtended::setIpConfig(IpParameterObject& parameters)
 
 void KnxIpSearchResponseExtended::setIpCurrentConfig(IpParameterObject& parameters)
 {
-    println("setIpCurrentConfig");
+    //println("setIpCurrentConfig");
     KnxIpConfigDIB _ipCurConfig(_data + currentPos, true);
     _ipCurConfig.length(LEN_IP_CURRENT_CONFIG_DIB);
     _ipCurConfig.code(IP_CUR_CONFIG);
     _ipCurConfig.address(parameters.propertyValue<uint32_t>(PID_CURRENT_IP_ADDRESS));
     _ipCurConfig.subnet(parameters.propertyValue<uint32_t>(PID_CURRENT_SUBNET_MASK));
     _ipCurConfig.gateway(parameters.propertyValue<uint32_t>(PID_CURRENT_DEFAULT_GATEWAY));
-    _ipCurConfig.dhcp(parameters.propertyValue<uint32_t>(PID_DHCP_BOOTP_SERVER));
+    _ipCurConfig.dhcp(0);
     _ipCurConfig.info1(parameters.propertyValue<uint8_t>(PID_CURRENT_IP_ASSIGNMENT_METHOD));
     _ipCurConfig.info2(0x00); //Reserved
 
@@ -113,7 +113,7 @@ void KnxIpSearchResponseExtended::setIpCurrentConfig(IpParameterObject& paramete
 
 void KnxIpSearchResponseExtended::setKnxAddresses(IpParameterObject& parameters, DeviceObject& deviceObject)
 {
-    println("setKnxAddresses");
+    //println("setKnxAddresses");
     KnxIpKnxAddressesDIB _knxAddresses(_data + currentPos);
     _knxAddresses.length(4); //minimum
     _knxAddresses.code(KNX_ADDRESSES);
@@ -136,7 +136,7 @@ void KnxIpSearchResponseExtended::setKnxAddresses(IpParameterObject& parameters,
 
 void KnxIpSearchResponseExtended::setTunnelingInfo(IpParameterObject& parameters, DeviceObject& deviceObject, KnxIpTunnelConnection tunnels[])
 {
-    println("setTunnelingInfo");
+    //println("setTunnelingInfo");
     KnxIpTunnelingInfoDIB _tunnelInfo(_data + currentPos);
     _tunnelInfo.length(4); //minlength
     _tunnelInfo.code(TUNNELING_INFO);
@@ -202,7 +202,7 @@ void KnxIpSearchResponseExtended::setTunnelingInfo(IpParameterObject& parameters
 
 void KnxIpSearchResponseExtended::setExtendedDeviceInfo()
 {
-    println("setExtendedDeviceInfo");
+    //println("setExtendedDeviceInfo");
     KnxIpExtendedDeviceInformationDIB _extended(_data + currentPos);
     _extended.length(LEN_EXTENDED_DEVICE_INFORMATION_DIB);
     _extended.code(EXTENDED_DEVICE_INFO);
diff --git a/src/knx/knx_ip_tunnel_connection.cpp b/src/knx/knx_ip_tunnel_connection.cpp
index 9d4fe2a..06a04a8 100644
--- a/src/knx/knx_ip_tunnel_connection.cpp
+++ b/src/knx/knx_ip_tunnel_connection.cpp
@@ -7,6 +7,11 @@ KnxIpTunnelConnection::KnxIpTunnelConnection()
 
 void KnxIpTunnelConnection::Reset()
 {
+    print("Close Tunnel-Connection[");
+    print("?");
+    print("], Channel: 0x");
+    println(ChannelId, 16);
+
     ChannelId = 0;
     IpAddress = 0;
     PortData = 0;
diff --git a/src/knx/tpuart_data_link_layer.cpp b/src/knx/tpuart_data_link_layer.cpp
index ed1012a..b5f15b7 100644
--- a/src/knx/tpuart_data_link_layer.cpp
+++ b/src/knx/tpuart_data_link_layer.cpp
@@ -656,6 +656,24 @@ void TpUartDataLinkLayer::requestConfig()
     if (markerMode())
         _platform.writeUart(U_CONFIGURE_REQ | U_CONFIGURE_MARKER_REQ);
 
+#endif
+
+    // Set Address for AutoACK Unicast
+    const uint16_t address = _deviceObject.individualAddress();
+    _platform.writeUart(U_SET_ADDRESS_REQ);
+    _platform.writeUart((address >> 8) & 0xFF);
+    _platform.writeUart(address & 0xFF);
+#ifdef NCN5120
+    _platform.writeUart(0xFF); // Dummy Byte needed by NCN only
+#endif
+
+    // Set Address for AutoACK Unicast
+    const uint16_t address = _deviceObject.individualAddress();
+    _platform.writeUart(U_SET_ADDRESS_REQ);
+    _platform.writeUart((address >> 8) & 0xFF);
+    _platform.writeUart(address & 0xFF);
+#ifdef NCN5120
+    _platform.writeUart(0xFF); // Dummy Byte needed by NCN only
 #endif
 
     // Deviating Config
diff --git a/src/rp2040_arduino_platform.cpp b/src/rp2040_arduino_platform.cpp
index 44ae730..1145a37 100644
--- a/src/rp2040_arduino_platform.cpp
+++ b/src/rp2040_arduino_platform.cpp
@@ -470,12 +470,7 @@ uint32_t RP2040ArduinoPlatform::currentDefaultGateway()
 }
 void RP2040ArduinoPlatform::macAddress(uint8_t* addr)
 {
-#if defined(KNX_IP_LAN)
-    addr = KNX_NETIF.getNetIf()->hwaddr;
-#else
-    uint8_t macaddr[6] = {0, 0, 0, 0, 0, 0};
-    addr = KNX_NETIF.macAddress(macaddr);
-#endif
+    KNX_NETIF.macAddress(addr);
 }
 
 // multicast