How To Find Your IP Address In Linux | ifconfig Command

In Linux, the ifconfig (interface configuration) command is commonly used to display and manage the network interfaces on your system, including the local IP address, network settings, and other related information. If you’re looking to find your IP address in a Linux-based environment, ifconfig is one of the easiest and most commonly used methods.

This guide provides step-by-step instructions on how to find your IP address using the ifconfig command.

What is an IP Address?

An IP address (Internet Protocol address) is a unique identifier assigned to each device that connects to a network, such as a computer, router, or smartphone. It serves two main functions:

• Identifying the device on the network.
• Enabling the device to communicate with other devices on the network or the internet.

In the context of Linux, the IP address can be either an IPv4 address (e.g., 192.168.1.10) or an IPv6 address (e.g., fe80::1ff:fe23:4567:890a).

Prerequisites

• A Linux-based operating system (e.g., Ubuntu, CentOS, Fedora, Debian, etc.)
• Terminal access with sufficient privileges to view network settings (typically no need for elevated privileges to run ifconfig for most systems).
• The ifconfig command should be installed by default on most Linux distributions. However, if not, you may need to install it (explained later).

Step-by-Step Guide to Find Your IP Address Using ifconfig

1. Open the Terminal:
   • On most Linux distributions, you can open the terminal using the following shortcut: Ctrl + Alt + T.
   • Alternatively, you can find the terminal application in your application menu.
2. Check for the ifconfig Command:
   • To check if ifconfig is installed on your system, type the following command and press Enter:

   ifconfig
   

   • If ifconfig is installed, it will display a list of network interfaces and their associated details.
   • If ifconfig is not found, you will need to install it (explained in the next section).
3. Install ifconfig if It’s Not Installed (Optional):
   • In newer versions of some Linux distributions (like Ubuntu), ifconfig may not be installed by default, as it has been replaced by ip from the iproute2 package. However, if you still prefer to use ifconfig, you can install the net-tools package.
   • On Ubuntu/Debian-based systems, run the following command to install net-tools (which includes ifconfig):

   sudo apt update
   sudo apt install net-tools
   

   • On CentOS/RHEL/Fedora, you can install it with:

   sudo yum install net-tools   # CentOS/RHEL 7 or older
   sudo dnf install net-tools   # CentOS/RHEL 8 or Fedora
   

4. Run the ifconfig Command:
   • Once ifconfig is installed, open the terminal and run the command:

   ifconfig
   

   • This command will display information about all available network interfaces on your system. The output may look something like this:

   eth0      Link encap:Ethernet  HWaddr 00:1A:2B:3C:4D:5E  
             inet addr:192.168.1.10  Bcast:192.168.1.255  Mask:255.255.255.0
             inet6 addr: fe80::21a:2bff:fe3c:4d5e/64 Scope:Link
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:12345 errors:0 dropped:0 overruns:0 frame:0
             TX packets:12345 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:1000 
             RX bytes:1234567 (1.2 MB)  TX bytes:1234567 (1.2 MB)
             Interrupt:20
   

   • This output may vary based on the network interfaces on your system, but you should look for the inet field, which displays your IPv4 address.
5. Locate Your IP Address:
   • In the output, find the network interface that you’re interested in (for example, eth0 for Ethernet or wlan0 for Wi-Fi).
   • The IP address will appear next to the inet keyword. In this case, the IP address is 192.168.1.10.

   Example of output (focus on inet addr):

   eth0      Link encap:Ethernet  HWaddr 00:1A:2B:3C:4D:5E  
             inet addr:192.168.1.10  Bcast:192.168.1.255  Mask:255.255.255.0
   

   • The inet addr field shows the IPv4 address.
   • If you need the IPv6 address, you can also find it under the inet6 field.

Understanding the ifconfig Output

Here’s an explanation of key fields in the ifconfig output:

1. eth0 (or wlan0, enp0s3, etc.): The name of the network interface. eth0 is typically used for wired Ethernet connections, and wlan0 is used for wireless connections.
2. inet addr: 192.168.1.10: This shows the IPv4 address assigned to the network interface. This is the address your machine uses to communicate on the local network or the internet.
3. Bcast:192.168.1.255: The broadcast address used for broadcasting messages to all devices on the local network.
4. Mask:255.255.255.0: The subnet mask, which defines the range of IP addresses that are considered part of the same network.
5. inet6: This shows the IPv6 address, which is used for communication over modern networks supporting IPv6.
6. Other Information:
   • RX and TX: These represent the number of packets received (RX) and transmitted (TX) on the interface.
   • HWaddr: The MAC address of the network interface, which is a unique hardware identifier.
   • MTU: The Maximum Transmission Unit, indicating the maximum size of packets that can be transmitted.

Finding Your Public IP Address

The ifconfig command only shows your local IP address, which is used within your local network. If you need to find your public IP address (the IP address that the internet sees), you will need to use an external service.

You can use the following commands in the terminal to check your public IP address:

1. Using curl (if installed):

   curl ifconfig.me
   

2. Using wget:

   wget -qO- ifconfig.me
   

These commands will show your public-facing IP address, assigned by your internet service provider (ISP), which might be the same for all devices behind your router or gateway.

Conclusion

Using the ifconfig command in Linux is a simple and effective way to find your IP address. It provides a detailed overview of your network interfaces, showing both IPv4 and IPv6 addresses. For finding your local IP address, you can easily locate it under the inet field. For the public IP address, external services like curl or wget can be used.

Although ifconfig is a classic tool for network configuration, newer Linux distributions may rely more on the ip command from the iproute2 package. However, ifconfig remains a powerful and widely used tool for network troubleshooting and configuration in many Linux environments.