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A Virtual Adapter is a non-physical network adapter installed on Windows with the purpose of providing a unique interface for this Driver, or other protocols, regardless of which physical network is active, A, B, or both.

 

Installation

To install a virtual network adapter on Windows 10, follow these procedures:

1.On the Start menu, open Device Manager.

2.Select the Network adapters item on the three of devices.

3.Select the Add legacy hardware option on the Action menu.

4.On the Add Hardware window, click Next and select the Install the hardware that I manually select from a list (Advanced) option and click Next.

5.Select the Network adapters item and click Next.

6.Select the Microsoft item on the Manufacturer list, select the KM-TEST Loopback adapter on the Network Adapter list, and click Next on the next screens.

7.Users can also use a virtual adapter that comes with the installation of Npcap library, but this adapter is a shortcut to the KM-Test Loopback adapter. This option can be selected during the installation of Npcap library.

 

Configuration

Once a virtual adapter is defines, enable this adapter to use the Npcap capture library and define a fixed IP address, according to the next procedures.

1.On the Start menu, open Control Panel and select the Network and Internet - Network Connections option.

2.Right-click the virtual adapter created previously and select the Properties option.

3.On the properties window, enable the smallest number of options possible to decrease traffic to the 61850 IEDs on the This connection uses the following items list. The main options are Npcap Packet Driver and Internet Protocol Version 4 (TCP/IPv4).

4.Double-click the Internet Protocol Version 4 (TCP/IPv4) option, select the Use the following IP address option on the General tab, inform a fixed and valid IP address to access the network of IEDs in the IP Address option, and click OK to apply changes.

 

Defining an MTU

A virtual interface, when installed, define by default an MTU (Maximum Transmission Unit) value practically limitless. But physical network adapters generally use an MTU value of 1500 bytes. In the current version of Elipse Software's PRP service, the MTU value is adjusted automatically, so that a frame generated by a virtual adapter can be transmitted to physical adapters. To check or adjust the MTU value for a network adapter permanently, which is the recommended procedure, execute the next steps.

1.Open a Command Prompt in Administrator mode. To do so, right click the icon of Command Prompt on the Start menu and select the Run as administrator option.

2.To check the index and value of MTU of existing interfaces, type the next command.

> netsh interface ipv4 show interfaces

 

3.To change the value of MTU of an interface, type the next command. The <Idx> parameter corresponds to the index of this interface and must be replaced by the value of the column Idx shown as the result of the previous command.

> netsh interface ipv4 set subinterface <Idx> mtu=1500 store=persistent

 

Linking a Virtual Adapter to this Driver

To ensure that MMS (Manufacturing Message Specification) messages of 61850 protocol are directed only to the virtual adapter and not to other adapters, users must inform this configuration to this Driver. This configuration can be executed by manually informing which adapter must be used by this Driver or informing, in the ServerName/Interface List option on the PRP tab, a list with the names of servers that execute this Driver and their respective IP addresses.

 

Manually Defining a Network Interface

1.Open the properties window of this Driver and, on the Setup tab, define the Physical Layer option with the Ethernet value.

2.On the Ethernet tab, select the Interface option and, on the list of addresses, select the IP address defined for the virtual adapter. This definition is mandatory for the service to start.

3.Return to the Setup tab, define the Physical Layer option with the value None  and click OK to save the configuration of this Driver.

 

Dynamically Defining a Network Interface

1.On the PRP tab, inform in the ServerName/Interface List option a list of names of servers (DNS) and IP addresses in the format ServerA:IPA;ServerB:IPB so that a single project file containing this Driver can be used without changes in at least two servers. When this Driver starts, it gets the name of the local computer and checks if there is on that list an IP address corresponding to this name. If true, this IP address is used as the IP address of the virtual interface.