diff --git a/Configuration.cpp b/Configuration.cpp
index 78f3dafa6..7f68bb417 100644
--- a/Configuration.cpp
+++ b/Configuration.cpp
@@ -166,6 +166,7 @@
 #include <QNetworkInterface>
 #include <QHostInfo>
 #include <QHostAddress>
+#include <QStandardItem>
 #include <QDebug>
 
 #include "pimpl_impl.hpp"
@@ -442,7 +443,8 @@ private:
   void load_audio_devices (QAudio::Mode, QComboBox *, QAudioDeviceInfo *);
   void update_audio_channels (QComboBox const *, int, QComboBox *, bool);
 
-  void load_network_interfaces (QComboBox *, QString const& current);
+  void load_network_interfaces (CheckableItemComboBox *, QStringList const& current);
+  QStringList get_selected_network_interfaces (CheckableItemComboBox *);
   Q_SLOT void host_info_results (QHostInfo);
   void check_multicast (QHostAddress const&);
 
@@ -653,7 +655,7 @@ private:
   bool udp_server_name_edited_;
   int dns_lookup_id_;
   port_type udp_server_port_;
-  QString udp_interface_name_;
+  QStringList udp_interface_names_;
   int udp_TTL_;
   QString n1mm_server_name_;
   port_type n1mm_server_port_;
@@ -754,7 +756,7 @@ QString Configuration::opCall() const {return m_->opCall_;}
 void Configuration::opCall (QString const& call) {m_->opCall_ = call;}
 QString Configuration::udp_server_name () const {return m_->udp_server_name_;}
 auto Configuration::udp_server_port () const -> port_type {return m_->udp_server_port_;}
-QString Configuration::udp_interface_name () const {return m_->udp_interface_name_;}
+QStringList Configuration::udp_interface_names () const {return m_->udp_interface_names_;}
 int Configuration::udp_TTL () const {return m_->udp_TTL_;}
 bool Configuration::accept_udp_requests () const {return m_->accept_udp_requests_;}
 QString Configuration::n1mm_server_name () const {return m_->n1mm_server_name_;}
@@ -1078,9 +1080,9 @@ Configuration::impl::impl (Configuration * self, QNetworkAccessManager * network
     });
 
   // set up dynamic loading of network interfaces
-  connect (ui_->udp_interface_combo_box, &LazyFillComboBox::about_to_show_popup, [this] () {
+  connect (ui_->udp_interfaces_combo_box, &LazyFillComboBox::about_to_show_popup, [this] () {
       QGuiApplication::setOverrideCursor (QCursor {Qt::WaitCursor});
-      load_network_interfaces (ui_->udp_interface_combo_box, udp_interface_name_);
+      load_network_interfaces (ui_->udp_interfaces_combo_box, udp_interface_names_);
       QGuiApplication::restoreOverrideCursor ();
     });
 
@@ -1362,10 +1364,10 @@ void Configuration::impl::initialize_models ()
   ui_->udp_server_line_edit->setText (udp_server_name_);
   on_udp_server_line_edit_editingFinished ();
   ui_->udp_server_port_spin_box->setValue (udp_server_port_);
-  load_network_interfaces (ui_->udp_interface_combo_box, udp_interface_name_);
-  if (!udp_interface_name_.size ())
+  load_network_interfaces (ui_->udp_interfaces_combo_box, udp_interface_names_);
+  if (!udp_interface_names_.size ())
     {
-      udp_interface_name_ = ui_->udp_interface_combo_box->currentData ().toString ();
+      udp_interface_names_ = get_selected_network_interfaces (ui_->udp_interfaces_combo_box);
     }
   ui_->udp_TTL_spin_box->setValue (udp_TTL_);
   ui_->accept_udp_requests_check_box->setChecked (accept_udp_requests_);
@@ -1545,7 +1547,7 @@ void Configuration::impl::read_settings ()
   rig_params_.split_mode = settings_->value ("SplitMode", QVariant::fromValue (TransceiverFactory::split_mode_none)).value<TransceiverFactory::SplitMode> ();
   opCall_ = settings_->value ("OpCall", "").toString ();
   udp_server_name_ = settings_->value ("UDPServer", "127.0.0.1").toString ();
-  udp_interface_name_ = settings_->value ("UDPInterface").toString ();
+  udp_interface_names_ = settings_->value ("UDPInterface").toStringList ();
   udp_TTL_ = settings_->value ("UDPTTL", 1).toInt ();
   udp_server_port_ = settings_->value ("UDPServerPort", 2237).toUInt ();
   n1mm_server_name_ = settings_->value ("N1MMServer", "127.0.0.1").toString ();
@@ -1675,7 +1677,7 @@ void Configuration::impl::write_settings ()
   settings_->setValue ("OpCall", opCall_);
   settings_->setValue ("UDPServer", udp_server_name_);
   settings_->setValue ("UDPServerPort", udp_server_port_);
-  settings_->setValue ("UDPInterface", udp_interface_name_);
+  settings_->setValue ("UDPInterface", QVariant::fromValue (udp_interface_names_));
   settings_->setValue ("UDPTTL", udp_TTL_);
   settings_->setValue ("N1MMServer", n1mm_server_name_);
   settings_->setValue ("N1MMServerPort", n1mm_server_port_);
@@ -2105,12 +2107,12 @@ void Configuration::impl::accept ()
   opCall_=ui_->opCallEntry->text();
 
   auto new_server = ui_->udp_server_line_edit->text ().trimmed ();
-  auto new_interface = ui_->udp_interface_combo_box->currentData ().toString ();
-  if (new_server != udp_server_name_ || new_interface != udp_interface_name_)
+  auto new_interfaces = get_selected_network_interfaces (ui_->udp_interfaces_combo_box);
+  if (new_server != udp_server_name_ || new_interfaces != udp_interface_names_)
     {
       udp_server_name_ = new_server;
-      udp_interface_name_ = new_interface;
-      Q_EMIT self_->udp_server_changed (udp_server_name_, udp_interface_name_);
+      udp_interface_names_ = new_interfaces;
+      Q_EMIT self_->udp_server_changed (udp_server_name_, udp_interface_names_);
     }
 
   auto new_port = ui_->udp_server_port_spin_box->value ();
@@ -2452,8 +2454,8 @@ void Configuration::impl::host_info_results (QHostInfo host_info)
 void Configuration::impl::check_multicast (QHostAddress const& ha)
 {
   auto is_multicast = is_multicast_address (ha);
-  ui_->udp_interface_label->setVisible (is_multicast);
-  ui_->udp_interface_combo_box->setVisible (is_multicast);
+  ui_->udp_interfaces_label->setVisible (is_multicast);
+  ui_->udp_interfaces_combo_box->setVisible (is_multicast);
   ui_->udp_TTL_label->setVisible (is_multicast);
   ui_->udp_TTL_spin_box->setVisible (is_multicast);
   if (isVisible ())
@@ -2993,28 +2995,53 @@ void Configuration::impl::load_audio_devices (QAudio::Mode mode, QComboBox * com
 }
 
 // load the available network interfaces into the selection combo box
-void Configuration::impl::load_network_interfaces (QComboBox * combo_box, QString const& current)
+void Configuration::impl::load_network_interfaces (CheckableItemComboBox * combo_box, QStringList const& current)
 {
   combo_box->clear ();
-  int current_index = -1;
-  for (auto const& interface : QNetworkInterface::allInterfaces ())
+  for (auto const& net_if : QNetworkInterface::allInterfaces ())
     {
-      if (interface.flags () & QNetworkInterface::IsUp)
+      auto flags = QNetworkInterface::IsUp | QNetworkInterface::CanMulticast;
+      if ((net_if.flags () & flags) == flags)
         {
-          auto const& name = interface.name ();
-          combo_box->addItem (interface.humanReadableName (), name);
-          // select the first loopback interface as a default to
-          // discourage spamming the network (possibly the Internet),
-          // particularly important with administratively scoped
-          // multicast UDP
-          if (name == current
-              || (!current.size () && (interface.flags () & QNetworkInterface::IsLoopBack)))
+          auto is_loopback = net_if.flags () & QNetworkInterface::IsLoopBack;
+          auto item = combo_box->addCheckItem (net_if.humanReadableName ()
+                                               , net_if.name ()
+                                               , is_loopback || current.contains (net_if.name ()) ? Qt::Checked : Qt::Unchecked);
+          item->setEnabled (!is_loopback);
+          auto tip = QString {"name(index): %1(%2) - %3"}.arg (net_if.name ()).arg (net_if.index ())
+                       .arg (net_if.flags () & QNetworkInterface::IsUp ? "Up" : "Down");
+          auto hw_addr = net_if.hardwareAddress ();
+          if (hw_addr.size ())
             {
-              current_index = combo_box->count () - 1;
+              tip += QString {"\nhw: %1"}.arg (net_if.hardwareAddress ());
             }
+          auto aes = net_if.addressEntries ();
+          if (aes.size ())
+            {
+              tip += "\naddresses:";
+              for (auto const& ae : aes)
+                {
+                  tip += QString {"\n  ip: %1/%2"}.arg (ae.ip ().toString ()).arg (ae.prefixLength ());
+                }
+            }
+          item->setToolTip (tip);
         }
     }
-  combo_box->setCurrentIndex (current_index);
+}
+
+// get the select network interfaces from the selection combo box
+QStringList Configuration::impl::get_selected_network_interfaces (CheckableItemComboBox * combo_box)
+{
+  QStringList interfaces;
+  auto model = static_cast<QStandardItemModel *> (combo_box->model ());
+  for (int row = 0; row < model->rowCount (); ++row)
+    {
+      if (Qt::Checked == model->item (row)->checkState ())
+        {
+          interfaces << model->item (row)->data ().toString ();
+        }
+    }
+  return interfaces;
 }
 
 // enable only the channels that are supported by the selected audio device
diff --git a/Configuration.hpp b/Configuration.hpp
index 403673663..b0f6bf75b 100644
--- a/Configuration.hpp
+++ b/Configuration.hpp
@@ -3,6 +3,7 @@
 
 #include <QObject>
 #include <QFont>
+#include <QString>
 
 #include "Radio.hpp"
 #include "models/IARURegions.hpp"
@@ -14,7 +15,6 @@
 class QSettings;
 class QWidget;
 class QAudioDeviceInfo;
-class QString;
 class QDir;
 class QNetworkAccessManager;
 class Bands;
@@ -151,7 +151,7 @@ public:
   void opCall (QString const&);
   QString udp_server_name () const;
   port_type udp_server_port () const;
-  QString udp_interface_name () const;
+  QStringList udp_interface_names () const;
   int udp_TTL () const;
   QString n1mm_server_name () const;
   port_type n1mm_server_port () const;
@@ -274,7 +274,7 @@ public:
   //
   // This signal is emitted when the UDP server changes
   //
-  Q_SIGNAL void udp_server_changed (QString& udp_server_name, QString const& network_interface) const;
+  Q_SIGNAL void udp_server_changed (QString& udp_server_name, QStringList const& network_interfaces) const;
   Q_SIGNAL void udp_server_port_changed (port_type server_port) const;
   Q_SIGNAL void udp_TTL_changed (int TTL) const;
   Q_SIGNAL void accept_udp_requests_changed (bool checked) const;
diff --git a/Configuration.ui b/Configuration.ui
index fd8fb8955..1b6ef8926 100644
--- a/Configuration.ui
+++ b/Configuration.ui
@@ -1893,17 +1893,17 @@ and DX Grid fields when a 73 or free text message is sent.</string>
              </widget>
             </item>
             <item row="2" column="0">
-             <widget class="QLabel" name="udp_interface_label">
+             <widget class="QLabel" name="udp_interfaces_label">
               <property name="text">
-               <string>Outgoing interface:</string>
+               <string>Outgoing interfaces:</string>
               </property>
               <property name="buddy">
-               <cstring>udp_interface_combo_box</cstring>
+               <cstring>udp_interfaces_combo_box</cstring>
               </property>
              </widget>
             </item>
             <item row="2" column="1">
-             <widget class="LazyFillComboBox" name="udp_interface_combo_box"/>
+             <widget class="CheckableItemComboBox" name="udp_interfaces_combo_box"/>
             </item>
             <item row="3" column="1">
              <widget class="QSpinBox" name="udp_TTL_spin_box">
@@ -3029,6 +3029,11 @@ Right click for insert and delete options.</string>
    <extends>QComboBox</extends>
    <header>widgets/LazyFillComboBox.hpp</header>
   </customwidget>
+  <customwidget>
+   <class>CheckableItemComboBox</class>
+   <extends>QComboBox</extends>
+   <header>widgets/CheckableItemComboBox.hpp</header>
+  </customwidget>
  </customwidgets>
  <tabstops>
   <tabstop>configuration_tabs</tabstop>
@@ -3111,7 +3116,7 @@ Right click for insert and delete options.</string>
   <tabstop>psk_reporter_tcpip_check_box</tabstop>
   <tabstop>udp_server_line_edit</tabstop>
   <tabstop>udp_server_port_spin_box</tabstop>
-  <tabstop>udp_interface_combo_box</tabstop>
+  <tabstop>udp_interfaces_combo_box</tabstop>
   <tabstop>udp_TTL_spin_box</tabstop>
   <tabstop>accept_udp_requests_check_box</tabstop>
   <tabstop>udpWindowToFront</tabstop>
@@ -3221,13 +3226,13 @@ Right click for insert and delete options.</string>
   </connection>
  </connections>
  <buttongroups>
-  <buttongroup name="split_mode_button_group"/>
+  <buttongroup name="TX_audio_source_button_group"/>
   <buttongroup name="CAT_stop_bits_button_group"/>
-  <buttongroup name="special_op_activity_button_group"/>
   <buttongroup name="CAT_handshake_button_group"/>
   <buttongroup name="CAT_data_bits_button_group"/>
   <buttongroup name="TX_mode_button_group"/>
+  <buttongroup name="special_op_activity_button_group"/>
   <buttongroup name="PTT_method_button_group"/>
-  <buttongroup name="TX_audio_source_button_group"/>
+  <buttongroup name="split_mode_button_group"/>
  </buttongroups>
 </ui>
diff --git a/Network/MessageClient.cpp b/Network/MessageClient.cpp
index 3474f19bb..2e721d5f7 100644
--- a/Network/MessageClient.cpp
+++ b/Network/MessageClient.cpp
@@ -59,7 +59,7 @@ public:
 
   enum StreamStatus {Fail, Short, OK};
 
-  void set_server (QString const& server_name, QString const& network_interface_name);
+  void set_server (QString const& server_name, QStringList const& network_interface_names);
   Q_SLOT void host_info_results (QHostInfo);
   void start ();
   void parse_message (QByteArray const&);
@@ -67,12 +67,12 @@ public:
   void heartbeat ();
   void closedown ();
   StreamStatus check_status (QDataStream const&) const;
-  void send_message (QByteArray const&);
-  void send_message (QDataStream const& out, QByteArray const& message)
+  void send_message (QByteArray const&, bool queue_if_pending = true);
+  void send_message (QDataStream const& out, QByteArray const& message, bool queue_if_pending = true)
   {
     if (OK == check_status (out))
       {
-        send_message (message);
+        send_message (message, queue_if_pending);
       }
     else
       {
@@ -89,7 +89,7 @@ public:
   QHostAddress server_;
   port_type server_port_;
   int TTL_;
-  QNetworkInterface network_interface_;
+  std::vector<QNetworkInterface> network_interfaces_;
   quint32 schema_;
   QTimer * heartbeat_timer_;
   std::vector<QHostAddress> blocked_addresses_;
@@ -101,10 +101,15 @@ public:
 
 #include "MessageClient.moc"
 
-void MessageClient::impl::set_server (QString const& server_name, QString const& network_interface_name)
+void MessageClient::impl::set_server (QString const& server_name, QStringList const& network_interface_names)
 {
   server_.setAddress (server_name);
-  network_interface_ = QNetworkInterface::interfaceFromName (network_interface_name);
+  network_interfaces_.clear ();
+  for (auto const& net_if_name : network_interface_names)
+    {
+      network_interfaces_.push_back (QNetworkInterface::interfaceFromName (net_if_name));
+    }
+
   if (server_.isNull () && server_name.size ()) // DNS lookup required
     {
       // queue a host address lookup
@@ -162,33 +167,10 @@ void MessageClient::impl::start ()
       return;
     }
 
-  TRACE_UDP ("Trying server:" << server_.toString () << "on interface:" << network_interface_.humanReadableName ());
-  QHostAddress interface_ip {QHostAddress::Any};
-  if (network_interface_.isValid ())
-    {
-      if (is_multicast_address (server_) && !(network_interface_.flags () & QNetworkInterface::CanMulticast))
-        {
-          Q_EMIT self_->error ("Network interface is not multicast capable, please try another");
-          return;
-        }
-      for (auto const& ae : network_interface_.addressEntries ())
-        {
-          auto const& ip = ae.ip ();
-          if (server_.protocol () == ip.protocol ())
-            {
-              interface_ip = ip;
-              break;
-            }
-        }
-      if (QHostAddress {QHostAddress::Any} == interface_ip)
-        {
-          Q_EMIT self_->error ("Network interface has no suitable address for server IP protocol, please try another");
-          pending_messages_.clear (); // discard
-          return;
-        }
-    }
+  TRACE_UDP ("Trying server:" << server_.toString ());
+  QHostAddress interface_addr {IPv6Protocol == server_.protocol () ? QHostAddress::AnyIPv6 : QHostAddress::AnyIPv4};
 
-  if (localAddress () != interface_ip)
+  if (localAddress () != interface_addr)
     {
       if (UnconnectedState != state () || state ())
         {
@@ -196,8 +178,8 @@ void MessageClient::impl::start ()
         }
       // bind to an ephemeral port on the selected interface and set
       // up for sending datagrams
-      bind (interface_ip);
-      setMulticastInterface (network_interface_);
+      bind (interface_addr);
+      qDebug () << "Bound to UDP port:" << localPort () << "on:" << localAddress ();
 
       // set multicast TTL to limit scope when sending to multicast
       // group addresses
@@ -210,7 +192,7 @@ void MessageClient::impl::start ()
   // clear any backlog
   while (pending_messages_.size ())
     {
-      send_message (pending_messages_.dequeue ());
+      send_message (pending_messages_.dequeue (), false);
     }
 }
 
@@ -438,14 +420,11 @@ void MessageClient::impl::heartbeat ()
    if (server_port_ && !server_.isNull ())
     {
       QByteArray message;
-      NetworkMessage::Builder hb {&message, NetworkMessage::Heartbeat, id_, schema_};
-      hb << NetworkMessage::Builder::schema_number // maximum schema number accepted
-         << version_.toUtf8 () << revision_.toUtf8 ();
-      if (OK == check_status (hb))
-        {
-          TRACE_UDP ("schema:" << schema_ << "max schema:" << NetworkMessage::Builder::schema_number << "version:" << version_ << "revision:" << revision_);
-          writeDatagram (message, server_, server_port_);
-        }
+      NetworkMessage::Builder out {&message, NetworkMessage::Heartbeat, id_, schema_};
+      out << NetworkMessage::Builder::schema_number // maximum schema number accepted
+          << version_.toUtf8 () << revision_.toUtf8 ();
+      TRACE_UDP ("schema:" << schema_ << "max schema:" << NetworkMessage::Builder::schema_number << "version:" << version_ << "revision:" << revision_);
+      send_message (out, message, false);
     }
 }
 
@@ -455,15 +434,12 @@ void MessageClient::impl::closedown ()
     {
       QByteArray message;
       NetworkMessage::Builder out {&message, NetworkMessage::Close, id_, schema_};
-      if (OK == check_status (out))
-        {
-          TRACE_UDP ("");
-          writeDatagram (message, server_, server_port_);
-        }
+      TRACE_UDP ("");
+      send_message (out, message, false);
     }
 }
 
-void MessageClient::impl::send_message (QByteArray const& message)
+void MessageClient::impl::send_message (QByteArray const& message, bool queue_if_pending)
 {
   if (server_port_)
     {
@@ -471,11 +447,15 @@ void MessageClient::impl::send_message (QByteArray const& message)
         {
           if (message != last_message_) // avoid duplicates
             {
-              writeDatagram (message, server_, server_port_);
+              for (auto const& net_if : network_interfaces_)
+                {
+                  setMulticastInterface (net_if);
+                  writeDatagram (message, server_, server_port_);
+                }
               last_message_ = message;
             }
         }
-      else
+      else if (queue_if_pending)
         {
           pending_messages_.enqueue (message);
         }
@@ -509,7 +489,7 @@ auto MessageClient::impl::check_status (QDataStream const& stream) const -> Stre
 
 MessageClient::MessageClient (QString const& id, QString const& version, QString const& revision,
                               QString const& server_name, port_type server_port,
-                              QString const& network_interface_name,
+                              QStringList const& network_interface_names,
                               int TTL, QObject * self)
   : QObject {self}
   , m_ {id, version, revision, server_port, TTL, this}
@@ -532,7 +512,7 @@ MessageClient::MessageClient (QString const& id, QString const& version, QString
                                          Q_EMIT error (m_->errorString ());
                                        }
                                        });
-  m_->set_server (server_name, network_interface_name);
+  m_->set_server (server_name, network_interface_names);
 }
 
 QHostAddress MessageClient::server_address () const
@@ -545,9 +525,9 @@ auto MessageClient::server_port () const -> port_type
   return m_->server_port_;
 }
 
-void MessageClient::set_server (QString const& server_name, QString const& network_interface_name)
+void MessageClient::set_server (QString const& server_name, QStringList const& network_interface_names)
 {
-  m_->set_server (server_name, network_interface_name);
+  m_->set_server (server_name, network_interface_names);
 }
 
 void MessageClient::set_server_port (port_type server_port)
diff --git a/Network/MessageClient.hpp b/Network/MessageClient.hpp
index d0066dbe4..cc348be2d 100644
--- a/Network/MessageClient.hpp
+++ b/Network/MessageClient.hpp
@@ -36,7 +36,7 @@ public:
   // messages will be silently dropped until a server host lookup is complete
   MessageClient (QString const& id, QString const& version, QString const& revision,
                  QString const& server_name, port_type server_port,
-                 QString const& network_interface_name,
+                 QStringList const& network_interface_names,
                  int TTL, QObject * parent = nullptr);
 
   // query server details
@@ -46,7 +46,7 @@ public:
   // initiate a new server host lookup or if the server name is empty
   // the sending of messages is disabled, if an interface is specified
   // then that interface is used for outgoing datagrams
-  Q_SLOT void set_server (QString const& server_name, QString const& network_interface_name);
+  Q_SLOT void set_server (QString const& server_name, QStringList const& network_interface_names);
 
   // change the server port messages are sent to
   Q_SLOT void set_server_port (port_type server_port = 0u);
diff --git a/UDPExamples/MessageAggregatorMainWindow.cpp b/UDPExamples/MessageAggregatorMainWindow.cpp
index d110bfc44..a0fe90c47 100644
--- a/UDPExamples/MessageAggregatorMainWindow.cpp
+++ b/UDPExamples/MessageAggregatorMainWindow.cpp
@@ -266,17 +266,17 @@ MessageAggregatorMainWindow::MessageAggregatorMainWindow ()
 void MessageAggregatorMainWindow::restart_server ()
 {
   QSet<QString> net_ifs;
-    if (network_interfaces_combo_box_->isVisible ())
-      {
-        auto model = static_cast<QStandardItemModel *> (network_interfaces_combo_box_->model ());
-        for (int row = 0; row < model->rowCount (); ++row)
-          {
-            if (Qt::Checked == model->item (row)->checkState ())
-              {
-                net_ifs << model->item (row)->data ().toString ();
-              }
-          }
-      }
+  if (network_interfaces_combo_box_->isVisible ())
+    {
+      auto model = static_cast<QStandardItemModel *> (network_interfaces_combo_box_->model ());
+      for (int row = 0; row < model->rowCount (); ++row)
+        {
+          if (Qt::Checked == model->item (row)->checkState ())
+            {
+              net_ifs << model->item (row)->data ().toString ();
+            }
+        }
+    }
     server_->start (port_spin_box_->value ()
                     , QHostAddress {multicast_group_line_edit_->text ()}
                     , net_ifs);
diff --git a/UDPExamples/UDPDaemon.cpp b/UDPExamples/UDPDaemon.cpp
index 78d1a0c52..2d028f074 100644
--- a/UDPExamples/UDPDaemon.cpp
+++ b/UDPExamples/UDPDaemon.cpp
@@ -65,14 +65,14 @@ public:
       {
         if (f != dial_frequency_)
           {
-            std::cout << tr ("%1(%2): Dial frequency changed to %3")
-              .arg (key_.second).arg (key_.first.toString ()).arg (f).toStdString () << std::endl;
+            std::cout << QString {"%1(%2): "}.arg (key_.second).arg (key_.first.toString ()).toStdString ()
+                      << QString {"Dial frequency changed to %1"}.arg (f).toStdString () << std::endl;
             dial_frequency_ = f;
           }
         if (mode + sub_mode != mode_)
           {
-            std::cout << tr ("%1(%2): Mode changed to %3")
-              .arg (key_.second).arg (key_.first.toString ()).arg (mode + sub_mode).toStdString () << std::endl;
+            std::cout << QString {"%1(%2): "}.arg (key_.second).arg (key_.first.toString ()).toStdString ()
+                      << QString {"Mode changed to %1"}.arg (mode + sub_mode).toStdString () << std::endl;
             mode_ = mode + sub_mode;
           }
       }
@@ -88,8 +88,8 @@ public:
                   << "Dt:" << delta_time << "Df:" << delta_frequency
                   << "mode:" << mode << "Confidence:" << (low_confidence ? "low" : "high")
                   << "On air:" << !off_air;
-        std::cout << tr ("%1(%2): Decoded %3")
-          .arg (key_.second).arg (key_.first.toString ()).arg (message).toStdString () << std::endl;
+        std::cout << QString {"%1(%2): "}.arg (key_.second).arg (key_.first.toString ()).toStdString ()
+                  << QString {"Decoded %1"}.arg (message).toStdString () << std::endl;
       }
   }
 
@@ -102,8 +102,9 @@ public:
         qDebug () << "new:" << is_new << "t:" << time << "snr:" << snr
                   << "Dt:" << delta_time << "Df:" << delta_frequency
                   << "drift:" << drift;
-        std::cout << tr ("%1(%2): WSPR decode %3 grid %4 power: %5")
-          .arg (key_.second).arg (key_.first.toString ()).arg (callsign).arg (grid).arg (power).toStdString ()
+        std::cout << QString {"%1(%2): "}.arg (key_.second).arg (key_.first.toString ()).toStdString ()
+                  << QString {"WSPR decode %1 grid %2 power: %3"}
+                       .arg (callsign).arg (grid).arg (power).toStdString ()
                   << "On air:" << !off_air << std::endl;
       }
   }
@@ -125,12 +126,13 @@ public:
                   << "my_grid:" << my_grid << "exchange_sent:" << exchange_sent
                   << "exchange_rcvd:" << exchange_rcvd << "prop_mode:" << prop_mode;
         std::cout << QByteArray {80, '-'}.data () << '\n';
-        std::cout << tr ("%1(%2): Logged %3 grid: %4 power: %5 sent: %6 recd: %7 freq: %8 time_off: %9 op: %10 my_call: %11 my_grid: %12 exchange_sent: %13 exchange_rcvd: %14 comments: %15 prop_mode: %16")
-          .arg (key_.second).arg (key.first.toString ()).arg (dx_call).arg (dx_grid).arg (tx_power)
-          .arg (report_sent).arg (report_received)
-          .arg (dial_frequency).arg (time_off.toString("yyyy-MM-dd hh:mm:ss.z")).arg (operator_call)
-          .arg (my_call).arg (my_grid).arg (exchange_sent).arg (exchange_rcvd)
-          .arg (comments).arg (prop_mode).toStdString ()
+        std::cout << QString {"%1(%2): "}.arg (key_.second).arg (key_.first.toString ()).toStdString ()
+                  << QString {"Logged %1 grid: %2 power: %3 sent: %4 recd: %5 freq: %6 time_off: %7 op: %8 my_call: %9 my_grid: %10 exchange_sent: %11 exchange_rcvd: %12 comments: %13 prop_mode: %14"}
+                       .arg (dx_call).arg (dx_grid).arg (tx_power)
+                       .arg (report_sent).arg (report_received)
+                       .arg (dial_frequency).arg (time_off.toString("yyyy-MM-dd hh:mm:ss.z")).arg (operator_call)
+                       .arg (my_call).arg (my_grid).arg (exchange_sent).arg (exchange_rcvd)
+                       .arg (comments).arg (prop_mode).toStdString ()
                   << std::endl;
       }
   }
diff --git a/widgets/CheckableItemComboBox.cpp b/widgets/CheckableItemComboBox.cpp
index 3ef926243..13115c993 100644
--- a/widgets/CheckableItemComboBox.cpp
+++ b/widgets/CheckableItemComboBox.cpp
@@ -25,7 +25,7 @@ public:
 };
 
 CheckableItemComboBox::CheckableItemComboBox (QWidget * parent)
-  : QComboBox {parent}
+  : LazyFillComboBox {parent}
   , model_ {new QStandardItemModel()}
 {
   setModel (model_.data ());
diff --git a/widgets/CheckableItemComboBox.hpp b/widgets/CheckableItemComboBox.hpp
index 2aa3e9831..21e751167 100644
--- a/widgets/CheckableItemComboBox.hpp
+++ b/widgets/CheckableItemComboBox.hpp
@@ -1,9 +1,10 @@
 #ifndef CHECKABLE_ITEM_COMBO_BOX_HPP__
 #define CHECKABLE_ITEM_COMBO_BOX_HPP__
 
-#include <QComboBox>
 #include <QScopedPointer>
 
+#include "LazyFillComboBox.hpp"
+
 class QStandardItemModel;
 class QStandardItem;
 
@@ -12,7 +13,7 @@ class QStandardItem;
  * http://stackoverflow.com/questions/8422760/combobox-of-checkboxes
  */
 class CheckableItemComboBox
-  : public QComboBox
+  : public LazyFillComboBox
 {
   Q_OBJECT
 
diff --git a/widgets/LazyFillComboBox.hpp b/widgets/LazyFillComboBox.hpp
index 37af60f0b..7ac828fed 100644
--- a/widgets/LazyFillComboBox.hpp
+++ b/widgets/LazyFillComboBox.hpp
@@ -10,7 +10,7 @@ class QWidget;
 //
 // QComboBox derivative that signals show and hide of the pop up list.
 //
-class LazyFillComboBox final
+class LazyFillComboBox
   : public QComboBox
 {
   Q_OBJECT
diff --git a/widgets/mainwindow.cpp b/widgets/mainwindow.cpp
index 6fb8e1a5a..89117ecd9 100644
--- a/widgets/mainwindow.cpp
+++ b/widgets/mainwindow.cpp
@@ -414,7 +414,7 @@ MainWindow::MainWindow(QDir const& temp_directory, bool multiple,
   m_messageClient {new MessageClient {QApplication::applicationName (),
         version (), revision (),
         m_config.udp_server_name (), m_config.udp_server_port (),
-        m_config.udp_interface_name (), m_config.udp_TTL (),
+        m_config.udp_interface_names (), m_config.udp_TTL (),
         this}},
   m_psk_Reporter {&m_config, QString {"WSJT-X v" + version () + " " + m_revision}.simplified ()},
   m_manual {&m_network_manager},
@@ -7826,7 +7826,7 @@ void MainWindow::networkError (QString const& e)
                                                         , MessageBox::Cancel))
     {
       // retry server lookup
-      m_messageClient->set_server (m_config.udp_server_name (), m_config.udp_interface_name ());
+      m_messageClient->set_server (m_config.udp_server_name (), m_config.udp_interface_names ());
     }
 }