ip Command in Linux: Network Configuration

Quick take: The ip command is the modern tool for Linux networking, replacing ifconfig and route. Use ip a to show addresses, ip r to show routes, and ip link set to bring interfaces up or down.

Introduction

The ip command is the modern, unified tool for inspecting and configuring Linux networking. It replaces the older ifconfig, route, and arp commands with a single, consistent interface organised into objects: address, link, route, and more.

This guide covers the everyday tasks — viewing IP addresses and interfaces, checking the routing table, and bringing links up or down.

Syntax

The basic syntax of the ip command is:

ip [OPTIONS] OBJECT { COMMAND }

Common Options and Parameters

The most useful options and parameters for the ip command:

Practical Examples

Real ip commands you can run today:

# Show all IP addresses
ip a
# Brief, readable address summary
ip -br a
# Show the routing table
ip r
# Show network interfaces
ip link
# Bring an interface up
sudo ip link set eth0 up
# Add an IP address to an interface
sudo ip addr add 192.168.1.50/24 dev eth0
# Show the default gateway
ip route | grep default

Making ip Changes Permanent

Anything you configure with the ip command lives only in memory and disappears at the next reboot. For permanent network settings you must edit your distribution's configuration layer, which reapplies them at boot.

On modern Ubuntu, that layer is Netplan: you describe interfaces in a YAML file under /etc/netplan/ and run sudo netplan apply. On systems using NetworkManager (common on desktops and RHEL-family servers), use nmcli or nmtui. The ip command remains the right tool for inspecting state and for temporary changes while testing — just remember to commit anything you want to keep to Netplan or NetworkManager.

Tips and Best Practices

• Use ip -br a for a clean, column-aligned view of interfaces and their addresses.
• Changes made with ip are not persistent — they reset on reboot. Use Netplan (Ubuntu) or NetworkManager for permanent configuration.
• ip a replaces ifconfig, and ip r replaces route -n on modern distributions.

Final Thoughts

The ip command is the one networking tool to learn on modern Linux, unifying address, link, and route management that used to need three separate commands. Memorise ip a, ip r, and ip link set, and remember that its changes are temporary — make them permanent through your distribution's network configuration. Pair it with ss to see active connections.