Network Information on Linux

This guide explains how to identify all relevant network information on Linux using standard command-line tools.
It is designed to work correctly even when multiple network interfaces are present (Ethernet, Wi-Fi, VPN, virtual interfaces).

All information in this guide is obtained using standard Linux networking commands available on most distributions.

Supported systems

This guide applies to most modern Linux distributions, including:

• Ubuntu
• Debian
• Fedora
• Arch Linux
• Linux Mint
• Raspberry Pi OS

Applies to systems using:

• Ethernet
• Wi-Fi
• VPN connections

What information you will find

This guide helps you identify:

• Local IP address (LAN)
• Router (gateway) IP address
• VPN IP address (if connected)
• MAC address (hardware address)
• The correct network interface to use

Commands used

Network information on Linux is obtained using the following commands:

ip addr
ip route

These commands display all network interfaces and routing information on the system.

How to run the commands

1. Open Terminal
2. Run:

ip addr

The output is divided into sections, one per network interface.

Understanding network interfaces

Each block in the output represents one network interface.

Common interface names on Linux include:

• eth0, eth1
  Ethernet interfaces (common on servers and Raspberry Pi)

• enpXsY
  Ethernet interfaces (predictable naming on modern systems)

• wlan0
  Wi-Fi interface (older naming)

• wlpXsY
  Wi-Fi interface (modern naming)

• tun0, tunX
  VPN interfaces (TUN-based VPNs)

• wg0
  WireGuard VPN interface

• lo
  Loopback interface (ignore)

Most systems show multiple interfaces. This is normal.

Which interface should you use?

In most cases, use:

• Ethernet interface (eth0, enpXsY) → if connected by cable
• Wi-Fi interface (wlan0, wlpXsY) → if connected via Wi-Fi

Ignore interfaces that:

• Are named lo
• Do not show an inet address
• Are clearly virtual or unused

If a VPN is connected, an additional VPN interface (tunX, wg0) will appear separately.

Local IP address (LAN)

The local IP address identifies the computer inside the local network.

To find it:

• Locate the active Ethernet or Wi-Fi interface
• Identify the line starting with inet

Example:

inet 192.168.1.42/24 brd 192.168.1.255 scope global dynamic

Meaning:

• 192.168.1.42 → local IP address
• /24 → subnet mask (255.255.255.0)

Typical local IP ranges:

• 192.168.x.x
• 10.x.x.x
• 172.16.x.x

Router (gateway) IP address

The router IP address is obtained using:

ip route

Example output:

default via 192.168.1.1 dev enp3s0

Meaning:

• 192.168.1.1 → router (default gateway)
• enp3s0 → interface used to reach the router

VPN IP address

A VPN IP address exists only when a VPN connection is active.

To find it:

• Look for interfaces such as tun0, tun1, or wg0
• Identify the inet value under that interface

Example:

wg0: inet 100.96.12.34/32 scope global

Notes:

• VPN IP is different from the local IP
• If no VPN interface appears, no VPN is connected

MAC address (hardware address)

The MAC address uniquely identifies a network interface.

To find it:

• Use the same interface used for the local IP
• Identify the line starting with link/ether

Example:

link/ether 3c:52:82:9a:b4:1f brd ff:ff:ff:ff:ff:ff

Important notes:

• Wi-Fi and Ethernet interfaces have different MAC addresses
• MAC addresses do not change between networks
• VPN interfaces use virtual addresses