When you are managing a Linux server, troubleshooting a network connection, or configuring a new firewall, the very first thing you must do is identify the network interfaces installed on your machine. You need to know if the server is connected via Ethernet or Wi-Fi, what IP address the router has assigned to it, and whether the interface is actually powered on.
For decades, Linux administrators used the venerable ifconfig command to find this information. However, ifconfig has been officially deprecated and is no longer installed by default on modern distributions like Ubuntu. It has been entirely replaced by the much more powerful ip command suite.
How to View All Network Interfaces
To see a complete list of every network adapter connected to your machine, alongside their current status, use the ip link command.
- Open your terminal or SSH into your Ubuntu server.
- Type the following command and press Enter:
ip link showThe terminal will output a numbered list.
The first interface (usually numbered 1:) is almost always lo, which stands for “loopback.” This is a virtual internal interface the computer uses to talk to itself. You can generally ignore it.
The subsequent interfaces are your actual hardware. If you see a name starting with en or eth (like enp3s0 or eth0), that is a physical wired Ethernet connection. If you see a name starting with wl (like wlan0 or wlp2s0), that is a wireless Wi-Fi card.
Look carefully at the brackets next to the interface name. If it says <BROADCAST,MULTICAST,UP,LOWER_UP>, the interface is physically turned on and detecting a cable connection.
How to Find Your IP Address
While ip link shows you the hardware, it does not show you your IP addresses. To see the actual networking configuration, you must use the ip addr (or ip a for short) command.
ip addr showThis command outputs the exact same list of hardware interfaces, but it adds several crucial lines of data below each one.
Look under your primary Ethernet or Wi-Fi interface for a line that begins with the word inet (which stands for Internet Network).
Directly next to inet, you will see your local IPv4 address (for example, 192.168.1.50/24 or 10.0.0.15/8). This is the exact address you will use to SSH into the machine or configure your router’s port forwarding rules. (The line below it, starting with inet6, displays your modern IPv6 address).
How to Output Cleaner Results
By default, the ip command outputs a massive wall of text that can be difficult to read quickly.
If you only want to see a clean, simplified table showing just the interface names and their corresponding IP addresses, use the -brief (or -br) flag:
ip -br addr showThe terminal will instantly output a beautifully formatted, three-column table displaying the interface name, its status (UP or DOWN), and its IP address, stripping away all the confusing MAC addresses and broadcast data.