def connect_to_network(self, network_name, network_href, fence_mode='bridged'):
        """
        Connect the vApp to an existing virtual network in the VDC.

        :param network_name: (str): The name of the virtual network.
        :param network_href: (str): A uri that points to the network resource.
        :param fence_mode: (str, optional):
        :return: (TaskType) a :class:`pyvcloud.schema.vcd.v1_5.schemas.admin.vCloudEntities.TaskType` object that can be used to monitor the request.

        """
        vApp_NetworkConfigSection = [section for section in self.me.get_Section() if section.__class__.__name__ == "NetworkConfigSectionType"][0]
        link = [link for link in vApp_NetworkConfigSection.get_Link() if link.get_type() == "application/vnd.vmware.vcloud.networkConfigSection+xml"][0]
        for networkConfig in vApp_NetworkConfigSection.get_NetworkConfig():
            if networkConfig.get_networkName() == network_name:
                task = TaskType()
                task.set_status("success")
                task.set_Progress("100")
                return task
        networkConfigSection = VAPP.create_networkConfigSection(network_name, network_href, fence_mode, vApp_NetworkConfigSection)
        output = StringIO()
        networkConfigSection.export(output,
            0,
            name_ = 'NetworkConfigSection',
            namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
            pretty_print = True)
        body = output.getvalue().\
            replace('Info msgid=""', "ovf:Info").replace("Info", "ovf:Info").replace(":vmw", "").replace("vmw:","")\
            .replace("RetainNetovf", "ovf").replace("ovf:InfoAcrossDeployments","RetainNetInfoAcrossDeployments")
        self.response = Http.put(link.get_href(), data=body, headers=self.headers, verify=self.verify, logger=self.logger)
        if self.response.status_code == requests.codes.accepted:
            return taskType.parseString(self.response.content, True)

 def set_syslog_conf(self, syslog_server_ip):
     headers = self.headers
     headers['Accept'] = 'application/*+xml;version=5.11'
     headers['Content-Type'] = 'application/vnd.vmware.vcloud.SyslogSettings+xml;version=5.11'
     # content_type = "application/vnd.vmware.vcloud.SyslogSettings+xml"
     body = ''
     if '' == syslog_server_ip:
         body = """
         <SyslogServerSettings xmlns="http://www.vmware.com/vcloud/v1.5"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.vmware.com/vcloud/v1.5 http://10.160.99.94/api/v1.5/schema/master.xsd">
               <TenantSyslogServerSettings>
               </TenantSyslogServerSettings>
           </SyslogServerSettings>
                 """
     else:
         body = """
         <SyslogServerSettings xmlns="http://www.vmware.com/vcloud/v1.5"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.vmware.com/vcloud/v1.5 http://10.160.99.94/api/v1.5/schema/master.xsd">
             <TenantSyslogServerSettings>
                 <SyslogServerIp>%s</SyslogServerIp>
             </TenantSyslogServerSettings>
         </SyslogServerSettings>
         """ % syslog_server_ip
     # '<SyslogServerSettings><TenantSyslogServerSettings><SyslogServerIp>%s</SyslogServerIp></TenantSyslogServerSettings></SyslogServerSettings>' % syslog_server_ip
     # link = filter(lambda link: link.get_type() == content_type, self.me.get_Link())
     self.response = requests.post(self.me.href+'/action/configureSyslogServerSettings', data=body, headers=headers, verify=self.verify)
     if self.response.status_code == requests.codes.accepted:
         task = taskType.parseString(self.response.content, True)
         return task

    def disconnect_from_network(self, network_name):
        """
        Disconnect the vApp from an existing virtual network in the VDC.

        :param network_name: (str): The name of the virtual network.
        :return: (TaskType) a :class:`pyvcloud.schema.vcd.v1_5.schemas.admin.vCloudEntities.TaskType` object that can be used to monitor the request.

        """

        networkConfigSection = [section for section in self.me.get_Section() if section.__class__.__name__ == "NetworkConfigSectionType"][0]
        link = [link for link in networkConfigSection.get_Link() if link.get_type() == "application/vnd.vmware.vcloud.networkConfigSection+xml"][0]
        found = -1
        for index, networkConfig in enumerate(networkConfigSection.get_NetworkConfig()):
            if networkConfig.get_networkName() == network_name:
                found = index
        if found != -1:
            networkConfigSection.NetworkConfig.pop(found)
            output = StringIO()
            networkConfigSection.export(output,
                0,
                name_ = 'NetworkConfigSection',
                namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
                pretty_print = True)
            body = output.getvalue().\
                    replace("vmw:", "").replace('Info xmlns:vmw="http://www.vmware.com/vcloud/v1.5" msgid=""', "ovf:Info").\
                    replace("/Info", "/ovf:Info")
            self.response = Http.put(link.get_href(), data=body, headers=self.headers, verify=self.verify, logger=self.logger)
            if self.response.status_code == requests.codes.accepted:
                return taskType.parseString(self.response.content, True)

    def disconnect_vms(self, network_name):
        children = self.me.get_Children()
        if children:
            vms = children.get_Vm()
            for vm in vms:
                networkConnectionSection = [section for section in vm.get_Section() if isinstance(section, NetworkConnectionSectionType)][0]
                link = [link for link in networkConnectionSection.get_Link() if link.get_type() == "application/vnd.vmware.vcloud.networkConnectionSection+xml"][0]
                found = -1
                primary = networkConnectionSection.get_PrimaryNetworkConnectionIndex()
                for index, networkConnection in enumerate(networkConnectionSection.NetworkConnection):
                       if networkConnection.get_network() == network_name:
                            found = index
                if found != -1:
                    if networkConnectionSection.NetworkConnection[found].get_NetworkConnectionIndex() != primary:
                        networkConnectionSection.NetworkConnection.pop(found)
                    else:
                        networkConnectionSection.NetworkConnection[found].set_network("None")
                    output = StringIO()
                    networkConnectionSection.export(output,
                    0,
                    name_ = 'NetworkConfigSection',
                    namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
                    pretty_print = True)
                    body = output.getvalue().\
                    replace("vmw:", "").replace('Info xmlns:vmw="http://www.vmware.com/vcloud/v1.5" msgid=""', "ovf:Info").\
                    replace("/Info", "/ovf:Info")

                    self.response = requests.put(link.get_href(), data=body, headers=self.headers, verify=self.verify)

                    if self.response.status_code == requests.codes.accepted:
                        return taskType.parseString(self.response.content, True)

 def connect_to_network(self, network_name, network_href, fence_mode="bridged"):
     vApp_NetworkConfigSection = [
         section for section in self.me.get_Section() if section.__class__.__name__ == "NetworkConfigSectionType"
     ][0]
     link = [
         link
         for link in vApp_NetworkConfigSection.get_Link()
         if link.get_type() == "application/vnd.vmware.vcloud.networkConfigSection+xml"
     ][0]
     networkConfigSection = VAPP.create_networkConfigSection(network_name, network_href, fence_mode)
     for networkConfig in vApp_NetworkConfigSection.get_NetworkConfig():
         if networkConfig.get_networkName() == network_name:
             task = TaskType()
             task.set_status("success")
             task.set_Progress("100")
             return task
         networkConfigSection.add_NetworkConfig(networkConfig)
     output = StringIO()
     networkConfigSection.export(
         output,
         0,
         name_="NetworkConfigSection",
         namespacedef_='xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
         pretty_print=False,
     )
     body = output.getvalue().replace('Info msgid=""', "ovf:Info").replace("/Info", "/ovf:Info").replace("vmw:", "")
     self.response = requests.put(link.get_href(), data=body, headers=self.headers, verify=self.verify)
     if self.response.status_code == requests.codes.accepted:
         return taskType.parseString(self.response.content, True)

 def connect_vms(self, network_name, connection_index,
                 connections_primary_index=None, ip_allocation_mode='DHCP',
                 mac_address=None, ip_address=None):
     children = self.me.get_Children()
     if children:
         vms = children.get_Vm()
         for vm in vms:
             new_connection = self._create_networkConnection(
                 network_name, connection_index, ip_allocation_mode,
                 mac_address, ip_address)
             networkConnectionSection = [section for section in vm.get_Section() if isinstance(section, NetworkConnectionSectionType)][0]
             self._modify_networkConnectionSection(
                 networkConnectionSection,
                 new_connection,
                 connections_primary_index)
             output = StringIO()
             networkConnectionSection.export(output,
                 0,
                 name_ = 'NetworkConnectionSection',
                 namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:vmw="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
                 pretty_print = True)
             body=output.getvalue().replace("vmw:Info", "ovf:Info")
             self.response = requests.put(vm.get_href() + "/networkConnectionSection/", data=body, headers=self.headers, verify=self.verify)
             if self.response.status_code == requests.codes.accepted:
                 return taskType.parseString(self.response.content, True)

 def disconnect_from_network(self, network_name):
     networkConfigSection = [
         section for section in self.me.get_Section() if section.__class__.__name__ == "NetworkConfigSectionType"
     ][0]
     link = [
         link
         for link in networkConfigSection.get_Link()
         if link.get_type() == "application/vnd.vmware.vcloud.networkConfigSection+xml"
     ][0]
     found = -1
     for index, networkConfig in enumerate(networkConfigSection.get_NetworkConfig()):
         if networkConfig.get_networkName() == network_name:
             found = index
     if found != -1:
         networkConfigSection.NetworkConfig.pop(found)
         output = StringIO()
         networkConfigSection.export(
             output,
             0,
             name_="NetworkConfigSection",
             namespacedef_='xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
             pretty_print=False,
         )
         body = (
             output.getvalue()
             .replace("vmw:", "")
             .replace('Info xmlns:vmw="http://www.vmware.com/vcloud/v1.5" msgid=""', "ovf:Info")
             .replace("/Info", "/ovf:Info")
         )
         self.response = requests.put(link.get_href(), data=body, headers=self.headers, verify=self.verify)
         if self.response.status_code == requests.codes.accepted:
             return taskType.parseString(self.response.content, True)

 def force_customization(self, vm_name):
     children = self.me.get_Children()
     if children:
         vms = [vm for vm in children.get_Vm() if vm.name == vm_name]
         if len(vms) == 1:
             sections = vms[0].get_Section()
             links = filter(lambda link: link.rel == "deploy", vms[0].Link)
             if len(links) == 1:
                 forceCustomizationValue = "true"
                 deployVAppParams = vcloudType.DeployVAppParamsType()
                 deployVAppParams.set_powerOn("true")
                 deployVAppParams.set_deploymentLeaseSeconds(0)
                 deployVAppParams.set_forceCustomization("true")
                 body = CommonUtils.convertPythonObjToStr(
                     deployVAppParams,
                     name="DeployVAppParams",
                     namespacedef='xmlns="http://www.vmware.com/vcloud/v1.5"',
                 )
                 headers = self.headers
                 headers["Content-type"] = "application/vnd.vmware.vcloud.deployVAppParams+xml"
                 self.response = requests.post(links[0].href, data=body, headers=headers, verify=self.verify)
                 if self.response.status_code == requests.codes.accepted:
                     return taskType.parseString(self.response.content, True)
                 else:
                     print self.response.content

    def customize_guest_os(self, vm_name, customization_script=None,
                           computer_name=None, admin_password=None,
                           reset_password_required=False):
        """
        Associate a customization script with a guest OS and execute the script.
        The VMware tools must be installed in the Guest OS.

        :param vm_name: (str): The name of the vm to be customized.
        :param customization_script: (str, Optional): The path to a file on the local file system containing the customization script.
        :param computer_name: (str, Optional): A new value for the the computer name. A default value for the template is used if a value is not set.
        :param admin_password: (str, Optional): A password value for the admin/root user. A password is autogenerated if a value is not supplied.
        :param reset_password_required: (bool): Force the user to reset the password on first login.
        :return: (TaskType) a :class:`pyvcloud.schema.vcd.v1_5.schemas.admin.vCloudEntities.TaskType` object that can be used to monitor the request. \n
                            if the task cannot be created a debug level log message is generated detailing the reason.

        """
        children = self.me.get_Children()
        if children:
            vms = [vm for vm in children.get_Vm() if vm.name == vm_name]
            if len(vms) == 1:
                sections = vms[0].get_Section()
                customization_section = [section for section in sections
                         if (section.__class__.__name__ ==
                             "GuestCustomizationSectionType")
                         ][0]
                customization_section.set_Enabled(True)
                customization_section.set_ResetPasswordRequired(
                    reset_password_required)
                customization_section.set_AdminAutoLogonEnabled(False)
                customization_section.set_AdminAutoLogonCount(0)
                if customization_script:
                    customization_section.set_CustomizationScript(
                        customization_script)
                if computer_name:
                    customization_section.set_ComputerName(computer_name)
                if admin_password:
                    customization_section.set_AdminPasswordEnabled(True)
                    customization_section.set_AdminPasswordAuto(False)
                    customization_section.set_AdminPassword(admin_password)
                output = StringIO()
                customization_section.export(output,
                    0,
                    name_ = 'GuestCustomizationSection',
                    namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
                    pretty_print = True)
                body = output.getvalue().\
                    replace("vmw:", "").replace('Info xmlns:vmw="http://www.vmware.com/vcloud/v1.5" msgid=""', "ovf:Info").\
                    replace("/Info", "/ovf:Info")
                headers = self.headers
                headers['Content-type'] = 'application/vnd.vmware.vcloud.guestcustomizationsection+xml'
                self.response = Http.put(customization_section.Link[0].href, data=body, headers=headers, verify=self.verify, logger=self.logger)
                if self.response.status_code == requests.codes.accepted:
                    return taskType.parseString(self.response.content, True)
                else:
                    Log.debug(self.logger, "failed; response status=%d, content=%s" % (self.response.status_code, self.response.text))

 def save_services_configuration(self):
     edgeGatewayServiceConfiguration = self.me.get_Configuration().get_EdgeGatewayServiceConfiguration()
     body = '<?xml version="1.0" encoding="UTF-8"?>' + \
            CommonUtils.convertPythonObjToStr(self.me.get_Configuration().get_EdgeGatewayServiceConfiguration(),
                                              name='EdgeGatewayServiceConfiguration',
                                              namespacedef='xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ')
     content_type = "application/vnd.vmware.admin.edgeGatewayServiceConfiguration+xml"
     link = filter(lambda link: link.get_type() == content_type, self.me.get_Link())
     self.response = requests.post(link[0].get_href(), data=body, headers=self.headers)
     if self.response.status_code == requests.codes.accepted:
         task = taskType.parseString(self.response.content, True)
         return task

    def connect_vms(self, network_name, connection_index,
                    connections_primary_index=None, ip_allocation_mode='DHCP',
                    mac_address=None, ip_address=None):
        """
        Attach vms to a virtual network.

        something helpful.

        :param network_name: (str): The network name to connect the VM to.
        :param connection_index: (str): Virtual slot number associated with this NIC. First slot number is 0.
        :param connections_primary_index: (str): Virtual slot number associated with the NIC that should be considered this \n
                  virtual machine's primary network connection. Defaults to slot 0.
        :param ip_allocation_mode: (str, optional): IP address allocation mode for this connection.

                                 * One of:

                                  - POOL (A static IP address is allocated automatically from a pool of addresses.)

                                  - DHCP (The IP address is obtained from a DHCP service.)

                                  - MANUAL (The IP address is assigned manually in the IpAddress element.)

                                  - NONE (No IP addressing mode specified.)

        :param mac_address: (str):    the MAC address associated with the NIC.
        :param ip_address: (str):     the IP address assigned to this NIC.
        :return: (TaskType) a :class:`pyvcloud.schema.vcd.v1_5.schemas.admin.vCloudEntities.TaskType` object that can be used to monitor the request.


        """
        children = self.me.get_Children()
        if children:
            vms = children.get_Vm()
            for vm in vms:
                new_connection = self._create_networkConnection(
                    network_name, connection_index, ip_allocation_mode,
                    mac_address, ip_address)
                networkConnectionSection = [section for section in vm.get_Section() if isinstance(section, NetworkConnectionSectionType)][0]
                self._modify_networkConnectionSection(
                    networkConnectionSection,
                    new_connection,
                    connections_primary_index)
                output = StringIO()
                networkConnectionSection.export(output,
                    0,
                    name_ = 'NetworkConnectionSection',
                    namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:vmw="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
                    pretty_print = True)
                body=output.getvalue().replace("vmw:Info", "ovf:Info")
                self.response = Http.put(vm.get_href() + "/networkConnectionSection/", data=body, headers=self.headers, verify=self.verify, logger=self.logger)
                if self.response.status_code == requests.codes.accepted:
                    return taskType.parseString(self.response.content, True)

    def modify_vm_memory(self, vm_name, new_size):
        """
        Modify the virtual Memory allocation for VM.

        :param vm_name: (str): The name of the vm to be customized.
        :param new_size: (int): The new memory allocation in MB.
        :return: (TaskType) a :class:`pyvcloud.schema.vcd.v1_5.schemas.admin.vCloudEntities.TaskType` object that can be used to monitor the request. \n
                            if the task cannot be created a debug level log message is generated detailing the reason.

        :raises: Exception: If the named VM cannot be located or another error occured.
        """
        children = self.me.get_Children()
        if children:
            vms = [vm for vm in children.get_Vm() if vm.name == vm_name]
            if len(vms) == 1:
                sections = vm.get_Section()
                virtualHardwareSection = filter(lambda section: section.__class__.__name__== "VirtualHardwareSection_Type", sections)[0]
                items = virtualHardwareSection.get_Item()
                memory = filter(lambda item: item.get_Description().get_valueOf_() == "Memory Size", items)[0]
                href = memory.get_anyAttributes_().get('{http://www.vmware.com/vcloud/v1.5}href')
                en = memory.get_ElementName()
                en.set_valueOf_('%s MB of memory' % new_size)
                memory.set_ElementName(en)
                vq = memory.get_VirtualQuantity()
                vq.set_valueOf_(new_size)
                memory.set_VirtualQuantity(vq)
                weight = memory.get_Weight()
                weight.set_valueOf_(str(int(new_size)*10))
                memory.set_Weight(weight)
                memory_string = CommonUtils.convertPythonObjToStr(memory, 'Memory')
                Log.debug(self.logger, "memory: \n%s" % memory_string)
                output = StringIO()
                memory.export(output,
                    0,
                    name_ = 'Item',
                    namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1" xmlns:rasd="http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_ResourceAllocationSettingData"',
                    pretty_print = True)
                body = output.getvalue().\
                    replace('Info msgid=""', "ovf:Info").replace("/Info", "/ovf:Info").\
                    replace("vmw:", "").replace("class:", "rasd:").replace("ResourceType", "rasd:ResourceType")
                headers = self.headers
                headers['Content-type'] = 'application/vnd.vmware.vcloud.rasdItem+xml'
                self.response = Http.put(href, data=body, headers=headers, verify=self.verify, logger=self.logger)
                if self.response.status_code == requests.codes.accepted:
                    return taskType.parseString(self.response.content, True)
                else:
                    raise Exception(self.response.status_code)
        raise Exception('can\'t find vm')

 def disconnect_from_networks(self):
     networkConfigSection = [section for section in self.me.get_Section() if section.__class__.__name__ == "NetworkConfigSectionType"][0]
     link = [link for link in networkConfigSection.get_Link() if link.get_type() == "application/vnd.vmware.vcloud.networkConfigSection+xml"][0]
     networkConfigSection.NetworkConfig[:] = []
     output = StringIO()
     networkConfigSection.export(output,
         0,
         name_ = 'NetworkConfigSection',
         namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
         pretty_print = False)
     body = output.getvalue().\
             replace("vmw:", "").replace('Info xmlns:vmw="http://www.vmware.com/vcloud/v1.5" msgid=""', "ovf:Info").\
             replace("/Info", "/ovf:Info")
     self.response = Http.put(link.get_href(), data=body, headers=self.headers, verify=self.verify, logger=self.logger)
     if self.response.status_code == requests.codes.accepted:
         return taskType.parseString(self.response.content, True)

    def allocate_public_ip(self):
        api_version = "5.11"
        headers = dict(self.headers)
        headers["Accept"] = "application/*+xml;version={0}".format(api_version)
        href = self.me.get_href() + "/action/manageExternalIpAddresses"
        body = """
        <ExternalIpAddressActionList
         xmlns="http://www.vmware.com/vcloud/networkservice/1.0">
        <Allocation>
            <NumberOfExternalIpAddressesToAllocate>1</NumberOfExternalIpAddressesToAllocate>
        </Allocation>
        </ExternalIpAddressActionList>
        """

        self.response = Http.put(href, data=body, headers=headers, verify=self.verify, logger=self.logger)
        if self.response.status_code == requests.codes.ok:
            task = taskType.parseString(self.response.content, True)
            return task

 def customize_guest_os(self, vm_name, customization_script=None, computer_name=None, admin_password=None):
     children = self.me.get_Children()
     if children:
         vms = [vm for vm in children.get_Vm() if vm.name == vm_name]
         if len(vms) == 1:
             sections = vms[0].get_Section()
             customization_section = [
                 section for section in sections if (section.__class__.__name__ == "GuestCustomizationSectionType")
             ][0]
             customization_section.set_AdminAutoLogonEnabled(False)
             customization_section.set_AdminAutoLogonCount(0)
             if customization_script:
                 customization_section.set_CustomizationScript(customization_script)
             if computer_name:
                 customization_section.set_ComputerName(computer_name)
             if admin_password:
                 customization_section.set_AdminPasswordEnabled(True)
                 customization_section.set_AdminPasswordAuto(False)
                 customization_section.set_ResetPasswordRequired(False)
                 customization_section.set_AdminPassword(admin_password)
             output = StringIO()
             customization_section.export(
                 output,
                 0,
                 name_="GuestCustomizationSection",
                 namespacedef_='xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
                 pretty_print=False,
             )
             body = (
                 output.getvalue()
                 .replace("vmw:", "")
                 .replace('Info xmlns:vmw="http://www.vmware.com/vcloud/v1.5" msgid=""', "ovf:Info")
                 .replace("/Info", "/ovf:Info")
             )
             headers = self.headers
             headers["Content-type"] = "application/vnd.vmware.vcloud.guestcustomizationsection+xml"
             self.response = requests.put(
                 customization_section.Link[0].href, data=body, headers=headers, verify=self.verify
             )
             if self.response.status_code == requests.codes.accepted:
                 return taskType.parseString(self.response.content, True)
             else:
                 print self.response.content

    def deallocate_public_ip(self, ip_address):
        api_version = '5.11'
        headers = dict(self.headers)
        headers['Accept']='application/*+xml;version={0}'.format(api_version)
        href = self.me.get_href() + '/action/manageExternalIpAddresses'
        body = """
        <ExternalIpAddressActionList
         xmlns="http://www.vmware.com/vcloud/networkservice/1.0">
        <Deallocation>
            <ExternalIpAddress>{0}</ExternalIpAddress>
        </Deallocation>
        </ExternalIpAddressActionList>
        """.format(ip_address)

        self.response = requests.put(href, data=body, headers=headers,
                                     verify=self.verify)
        if self.response.status_code == requests.codes.ok:
            task = taskType.parseString(self.response.content, True)
            return task

    def disconnect_vms(self, network_name=None):
        """
        Disconnect the vm from the vapp network.

        :param network_name: (string): The name of the vApp network. If None, then disconnect from all the networks.
        :return: (bool): True if the user was vApp was successfully deployed, False otherwise.

        """
        children = self.me.get_Children()
        if children:
            vms = children.get_Vm()
            for vm in vms:
                Log.debug(self.logger, "child VM name=%s" % vm.get_name())
                networkConnectionSection = [section for section in vm.get_Section() if isinstance(section, NetworkConnectionSectionType)][0]
                found = -1
                if network_name is None:
                    networkConnectionSection.set_NetworkConnection([])
                    found = 1
                else:
                    for index, networkConnection in enumerate(networkConnectionSection.get_NetworkConnection()):
                        if networkConnection.get_network() == network_name:
                            found = index
                            break
                    if found != -1:
                        networkConnectionSection.NetworkConnection.pop(found)
                if found != -1:
                    output = StringIO()
                    networkConnectionSection.export(output,
                        0,
                        name_ = 'NetworkConnectionSection',
                        namespacedef_ = 'xmlns="http://www.vmware.com/vcloud/v1.5" xmlns:vmw="http://www.vmware.com/vcloud/v1.5" xmlns:ovf="http://schemas.dmtf.org/ovf/envelope/1"',
                        pretty_print = True)
                    body=output.getvalue().replace("vmw:Info", "ovf:Info")
                    self.response = Http.put(vm.get_href() + "/networkConnectionSection/", data=body, headers=self.headers, verify=self.verify, logger=self.logger)
                    if self.response.status_code == requests.codes.accepted:
                        return taskType.parseString(self.response.content, True)
        task = TaskType()
        task.set_status("success")
        task.set_Progress("100")
        return task

    def execute(self, operation, http, body=None, targetVM=None):
        """
        Execute an operation against a VM as an Asychronous Task.

        :param operation: (str): The command to execute
        :param http: (str): The http operation.
        :param body: (str, optional): a body for the http request
        :param targetVM: (str, optional): The name of the VM that will be the target of the request.
        :return: (TaskType or Bool) a :class:`pyvcloud.schema.vcd.v1_5.schemas.admin.vCloudEntities.TaskType` object that can be used to monitor the request. \n
                Or False if the request failed, error and debug level messages are logged.

        """
        vApp = targetVM if targetVM else self.me
        link = filter(lambda link: link.get_rel() == operation, vApp.get_Link())
        if not link:
            Log.error(self.logger, "link not found; rel=%s" % operation)
            Log.debug(self.logger, "vApp href=%s, name=%s" % (vApp.get_href(), vApp.get_name()))
            return False
        else:
            if http == "post":
                headers = self.headers
                if body and body.startswith('<DeployVAppParams '):
                    headers['Content-type'] = 'application/vnd.vmware.vcloud.deployVAppParams+xml'
                elif body and body.startswith('<UndeployVAppParams '):
                    headers['Content-type'] = 'application/vnd.vmware.vcloud.undeployVAppParams+xml'
                elif body and body.startswith('<CreateSnapshotParams '):
                    headers['Content-type'] = 'application/vnd.vmware.vcloud.createSnapshotParams+xml'
                self.response = Http.post(link[0].get_href(), data=body, headers=headers, verify=self.verify, logger=self.logger)
            elif http == "put":
                self.response = Http.put(link[0].get_href(), data=body, headers=self.headers, verify=self.verify, logger=self.logger)
            else:
                self.response = Http.delete(link[0].get_href(), headers=self.headers, verify=self.verify, logger=self.logger)
            if self.response.status_code == requests.codes.accepted:
                return taskType.parseString(self.response.content, True)
            else:
                Log.debug(self.logger, "failed; response status=%d, content=%s" % (self.response.status_code, self.response.text))
                return False

    def force_customization(self, vm_name, power_on=True):
        """
        Force the guest OS customization script to be run for a specific vm in the vApp.
        A customization script must have been previously associated with the VM
        using the pyvcloud customize_guest_os method or using the vCD console
        The VMware tools must be installed in the Guest OS.

        :param vm_name: (str): The name of the vm to be customized.
        :param power_on (bool): Wether to power the vm on after customization or not
        :return: (TaskType) a :class:`pyvcloud.schema.vcd.v1_5.schemas.admin.vCloudEntities.TaskType` object that can be used to monitor the request.b\n
                            if the task cannot be created a debug level log message is generated detailing the reason.

        """
        children = self.me.get_Children()
        if children:
            vms = [vm for vm in children.get_Vm() if vm.name == vm_name]
            if len(vms) == 1:
                sections = vms[0].get_Section()
                links = filter(lambda link: link.rel== "deploy", vms[0].Link)
                if len(links) == 1:
                    forceCustomizationValue = 'true'
                    deployVAppParams = vcloudType.DeployVAppParamsType()
                    if power_on:
                        deployVAppParams.set_powerOn('true')
                    else:
                        deployVAppParams.set_powerOn('false')
                    deployVAppParams.set_deploymentLeaseSeconds(0)
                    deployVAppParams.set_forceCustomization('true')
                    body = CommonUtils.convertPythonObjToStr(deployVAppParams, name = "DeployVAppParams",
                            namespacedef = 'xmlns="http://www.vmware.com/vcloud/v1.5"')
                    headers = self.headers
                    headers['Content-type'] = 'application/vnd.vmware.vcloud.deployVAppParams+xml'
                    self.response = Http.post(links[0].href, data=body, headers=headers, verify=self.verify, logger=self.logger)
                    if self.response.status_code == requests.codes.accepted:
                        return taskType.parseString(self.response.content, True)
                    else:
                        Log.debug(self.logger, "response status=%d, content=%s" % (self.response.status_code, self.response.text))