Network handler for UDP port allocation and server network interfaces.

gns3server/modules/port_manager.py

@@ -51,6 +51,21 @@ class PortManager:
         else:
             self._console_host = host
 
+        assert not hasattr(PortManager, "_instance")
+        PortManager._instance = self
+
+    @classmethod
+    def instance(cls):
+        """
+        Singleton to return only one instance of PortManager.
+
+        :returns: instance of PortManager
+        """
+
+        if not hasattr(cls, "_instance") or cls._instance is None:
+            cls._instance = cls()
+        return cls._instance
+
     @property
     def console_host(self):
 

gns3server/modules/virtualbox/virtualbox_vm.py

@@ -807,7 +807,10 @@ class VirtualBoxVM(BaseVM):
             yield from self._control_vm("nic{} null".format(adapter_id + 1))
 
         nio = adapter.get_nio(0)
+        if str(nio) == "NIO UDP":
+            self.manager.port_manager.release_udp_port(nio.lport)
         adapter.remove_nio(0)
+
         log.info("VirtualBox VM '{name}' [{uuid}]: {nio} removed from adapter {adapter_id}".format(name=self.name,
                                                                                                    uuid=self.uuid,
                                                                                                    nio=nio,

gns3server/modules/vpcs/vpcs_vm.py

@@ -343,7 +343,10 @@ class VPCSVM(BaseVM):
                                                                                        port_id=port_id))
 
         nio = self._ethernet_adapter.get_nio(port_id)
+        if str(nio) == "NIO UDP":
+            self.manager.port_manager.release_udp_port(nio.lport)
         self._ethernet_adapter.remove_nio(port_id)
+
         log.info("VPCS {name} [{uuid}]: {nio} removed from port {port_id}".format(name=self._name,
                                                                                   uuid=self.uuid,
                                                                                   nio=nio,