1 files changed, 8 insertions, 0 deletions

diff --git a/noncore/net/wellenreiter/gui/wellenreiter.cpp b/noncore/net/wellenreiter/gui/wellenreiter.cpp
index db68e5b..67e3940 100644
--- a/noncore/net/wellenreiter/gui/wellenreiter.cpp
+++ b/noncore/net/wellenreiter/gui/wellenreiter.cpp
@@ -503,25 +503,33 @@ void Wellenreiter::startClicked()
     if ( ( interface == "" ) || ( cardtype == 0 ) )
     {
         QMessageBox::information( this, "Wellenreiter II",
                                   tr( "Your device is not\nproperly configured. Please reconfigure!" ) );
         return;
     }
 
     // configure device
     ONetwork* net = ONetwork::instance();
 
     // TODO: check if interface is wireless and support sniffing for non-wireless interfaces
 
+    if ( !net->isPresent( interface ) )
+    {
+        QMessageBox::information( this, "Wellenreiter II",
+                                  tr( "The configured device (%1)\nis not available on this system\n. Please reconfigure!" ).arg( interface ) );
+        return;
+    }
+
     iface = static_cast<OWirelessNetworkInterface*>(net->interface( interface )); // fails if network is not wireless!
+    assert( iface );
 
     // bring device UP
     if ( cardtype != DEVTYPE_FILE )
     {
         iface->setUp( true );
         if ( !iface->isUp() )
         {
             QMessageBox::warning( this, "Wellenreiter II",
                                 tr( "Can't bring interface '%1' up:\n" ).arg( iface->name() ) + strerror( errno ) );
             return;
         }
     }