Checking the IP address on a Linux system is a fundamental task for network configuration and troubleshooting. Whether you are setting up a new server, diagnosing network issues, or simply curious about your network settings, knowing how to find your IP address is essential. This article will guide you through various methods to check the IP address on a Linux system.

Method 1: Using the ip Command

The ip command is a powerful tool for network configuration in Linux. It can be used to display and manipulate routing, devices, policy routing, and tunnels.

Example:

ip addr show

This command will display detailed information about all network interfaces, including their IP addresses. Look for the inet entry under the desired interface (e.g., eth0, wlan0).

Method 2: Using the ifconfig Command

The ifconfig command is another traditional tool for network interface configuration. Although it is deprecated in favour of the ip command, it is still widely used and available in many distributions.

Example:

ifconfig

This command will display information about all network interfaces. The IP address will be listed next to inet addr for each interface.

Method 3: Using the hostname Command

The hostname command with the -I option can be used to display the IP address(es) of the host.

Example:

hostname -I

This command will output the IP address(es) assigned to the host.

Method 4: Checking the /etc/network/interfaces File

For systems that use the /etc/network/interfaces file for network configuration, you can check this file to find static IP address assignments.

Example:

cat /etc/network/interfaces

Look for lines starting with address, netmask, and gateway to find the IP address configuration.

Method 5: Using the nmcli Command

The nmcli command is a command-line client for NetworkManager, a tool for managing network configurations.

Example:

nmcli device show

This command will display detailed information about all network devices, including their IP addresses.

Method 6: Using the ip route Command

The ip route command can be used to display the routing table, which includes the default gateway and the IP address of the interface used to reach it.

Example:

ip route

Look for the line starting with default via, which will show the default gateway and the interface's IP address.

Conclusion

There are multiple ways to check the IP address on a Linux system, each with its own advantages. Whether you prefer the modern ip command, the traditional ifconfig, or other tools like hostname, nmcli, or checking configuration files, you can easily find the IP address information you need.