diff --git a/gns3server/modules/virtualbox/virtualbox_vm.py b/gns3server/modules/virtualbox/virtualbox_vm.py
index aff3c3bf..b4b2678c 100644
--- a/gns3server/modules/virtualbox/virtualbox_vm.py
+++ b/gns3server/modules/virtualbox/virtualbox_vm.py
@@ -62,7 +62,7 @@ class VirtualBoxVM(BaseVM):
 
         # VirtualBox settings
         self._adapters = adapters
-        self._ethernet_adapters = []
+        self._ethernet_adapters = {}
         self._headless = False
         self._enable_remote_console = False
         self._vmname = vmname
@@ -213,7 +213,7 @@ class VirtualBoxVM(BaseVM):
             except VirtualBoxError as e:
                 log.warn("Could not deactivate the first serial port: {}".format(e))
 
-            for adapter_number in range(0, len(self._ethernet_adapters)):
+            for adapter_number in range(0, self._adapters):
                 nio = self._ethernet_adapters[adapter_number].get_nio(0)
                 if nio:
                     yield from self._modify_vm("--nictrace{} off".format(adapter_number + 1))
@@ -308,7 +308,7 @@ class VirtualBoxVM(BaseVM):
             self._manager.port_manager.release_tcp_port(self._console, self._project)
             self._console = None
 
-        for adapter in self._ethernet_adapters:
+        for adapter in self._ethernet_adapters.values():
             if adapter is not None:
                 for nio in adapter.ports.values():
                     if nio and isinstance(nio, NIOUDP):
@@ -483,12 +483,12 @@ class VirtualBoxVM(BaseVM):
 
         # check for the maximum adapters supported by the VM
         self._maximum_adapters = yield from self._get_maximum_supported_adapters()
-        if len(self._ethernet_adapters) > self._maximum_adapters:
+        if adapters > self._maximum_adapters:
             raise VirtualBoxError("Number of adapters above the maximum supported of {}".format(self._maximum_adapters))
 
         self._ethernet_adapters.clear()
         for adapter_number in range(0, adapters):
-            self._ethernet_adapters.append(EthernetAdapter())
+            self._ethernet_adapters[adapter_number] = EthernetAdapter()
 
         self._adapters = len(self._ethernet_adapters)
         log.info("VirtualBox VM '{name}' [{id}] has changed the number of Ethernet adapters to {adapters}".format(name=self.name,
@@ -643,7 +643,7 @@ class VirtualBoxVM(BaseVM):
         """
 
         nic_attachments = yield from self._get_nic_attachements(self._maximum_adapters)
-        for adapter_number in range(0, len(self._ethernet_adapters)):
+        for adapter_number in range(0, self._adapters):
             attachment = nic_attachments[adapter_number]
             if attachment == "null":
                 # disconnect the cable if no backend is attached.
@@ -683,8 +683,12 @@ class VirtualBoxVM(BaseVM):
                 if nio.capturing:
                     yield from self._modify_vm("--nictrace{} on".format(adapter_number + 1))
                     yield from self._modify_vm('--nictracefile{} "{}"'.format(adapter_number + 1, nio.pcap_output_file))
+            else:
+                yield from self._modify_vm("--nic{} null".format(adapter_number + 1))
+                yield from self._modify_vm("--cableconnected{} off".format(adapter_number + 1))
+
 
-        for adapter_number in range(len(self._ethernet_adapters), self._maximum_adapters):
+        for adapter_number in range(self._adapters, self._maximum_adapters):
             log.debug("disabling remaining adapter {}".format(adapter_number))
             yield from self._modify_vm("--nic{} none".format(adapter_number + 1))