About External Network Modifiers

External Network Modifiers (ENMs) provide the ability to specify when applications or scripts, for example, a VPN application, should perform their own network configuration external to that specified in the NCP and Location profiles. ENMs can also be defined as services or applications that directly modify the network configuration when they are enabled or disabled. ENMs are configured and monitored in the GUI by using the Network Modifiers dialog.

An ENM can be started and stopped manually, as required. An ENM can also be started automatically, according to user-defined rules. To be managed by using this dialog, a network modifier application must either be implemented as a command-line tool, or as an SMF service.

To learn more about how to create and manage ENMs by using the CLI, see Creating an ENM Profile.

About the Network Modifiers Dialog

This dialog is used to add or remove, start and stop, and edit ENMs, applications that are capable of creating and modifying network configuration.

Figure 4-7 Network Modifiers Dialog

Open the dialog by using one of the following methods:

• Click the Modifiers button in the Connection Status view of the Network Preferences dialog.

• Right-click the Network Status notification icon, then choose the Network Modifier Preferences menu item.

The main section of the dialog Available network modifiers that displays the following information for each ENM:

• Activation state icon (Manual or Conditional)

• User-defined name (Modifier Name), for example, “OpenVPN”

• Current status, “Running” or “Stopped”

The Start/Stop according to rules check box is checked if the selected network modifier application has a Conditional activation type, and unchecked if the activation type is Manual. To change the activation type, toggle the check box.

How to Add a Command-Line ENM

The following procedure describes how to add a command-line ENM. For information about adding a network modifier application service, see the online help.

1. Open the Network Modifiers dialog by using one of the following methods:

   • From then Connection Status view of the Network Preferences dialog, click the Modifiers button.

   • Right-click the Network Status notification icon, then choose the Network Modifier Preferences menu item.

2. Click the Add button.
3. Type the name of the new network modifier application.
4. To add a new entry or cancel your changes, choose one of the following:
   • To add a new entry that has the Manual activation type, press Enter or Tab.

     The two Manage modifiers radio buttons are enabled. The first of these, Command Line Applications, is selected by default. The Start and Stop command fields, and the two Browse buttons, are also enabled.

   • To cancel your changes, press Escape.
5. Type the command that starts the network modifier application into the Start Command field.

   Alternatively, you can use the Browse button to open a file chooser dialog, where you can select the command to use.

   The Start button remains disabled for the network modifier application until a valid command has been typed into this field.

6. Type the command that stops the network modifier application into the Stop Command field.

   Alternatively, you can use the Browse button to open a file chooser dialog, where you can select the command to use.

   The Stop button remains disabled for the network modifier application until a valid command has been typed into this field.

7. To add this application, click OK.

   The external network modifier is added.