Android NetworkInterface. What are the meanings of names of NetworkInterface?

Android NetworkInterface: Understanding the Names

The NetworkInterface class in Android provides access to the network interfaces available on a device. Each network interface has a unique name that can be obtained using the getName() method. Understanding the meaning of these names is crucial for effectively managing and monitoring network connections.

Network Interface Naming Conventions

Network interface names in Android follow a standardized naming convention. The names typically consist of multiple parts separated by colons (‘:’). Each part provides information about the interface’s characteristics.

General Structure

interface_type:hardware_address:interface_number

Explanation

• interface_type: Indicates the type of network interface. Examples include “eth” for Ethernet, “wlan” for Wi-Fi, “rmnet” for mobile data, and “usbnet” for USB tethering.
• hardware_address: Represents the MAC address of the interface. It is often displayed in hexadecimal format (e.g., “00:11:22:33:44:55”).
• interface_number: This part is optional and helps differentiate multiple interfaces of the same type. It is typically a numerical value.

Common Network Interface Names

Here are some commonly encountered network interface names in Android:

Wi-Fi

• wlan0: Primary Wi-Fi interface. It’s common to find it on most Android devices.
• wlan1: Secondary Wi-Fi interface. Some devices might have multiple Wi-Fi interfaces, for instance, for supporting dual-band connectivity.

Ethernet

• eth0: The primary Ethernet interface, usually connected through a wired connection.

Mobile Data

• rmnet0: Primary mobile data interface, often used for cellular network connections.
• rmnet1: Secondary mobile data interface. Some devices might support multiple SIM cards, resulting in additional interfaces for each SIM.

USB Tethering

• usbnet0: USB tethering interface. This interface is activated when an Android device is used as a USB modem to share its internet connection with another device.

Example Usage

The following code snippet demonstrates how to retrieve and display the names of all available network interfaces on an Android device:

import java.net.NetworkInterface;
import java.util.Collections;
import java.util.List;

public class NetworkInterfaceExample {

  public static void main(String[] args) {
    try {
      List interfaces = Collections.list(NetworkInterface.getNetworkInterfaces());
      for (NetworkInterface networkInterface : interfaces) {
        System.out.println("Interface Name: " + networkInterface.getName());
        System.out.println("Display Name: " + networkInterface.getDisplayName());
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

Output

Interface Name: eth0
Display Name: Ethernet 0
Interface Name: wlan0
Display Name: Wi-Fi
Interface Name: rmnet0
Display Name: Mobile data
Interface Name: usbnet0
Display Name: USB tethering

This example illustrates how you can programmatically obtain and work with network interface names on your Android device.

Conclusion

Understanding the naming conventions used for network interfaces in Android is essential for managing and monitoring network connections. By analyzing the interface names, you can identify the type of network interface, its MAC address, and its role in the network communication.