A network interface is a device or a point of connection between a device and a private or public network. In most cases, a network interface is a physical card such as a wireless adapter, a network card, etc. However, this does not necessarily mean that a network interface should be a physical device. For example, a loopback adapter that is not physically visible is implemented by software and available on all devices.”
This quick tutorial will show you how to set the default interface in Linux.
Method 1 – Turn Off Adapters
The simplest way to set your default network interface is by disabling all other interfaces. For example, in Linux, you can use the GUI network manager or the terminal.
Suppose you have a wireless adapter and you wish to use the Ethernet adapter; in that case, you can bring down the wifi adapter using the command:
$ sudo ifconfig eth0 up
The above commands will shut down the wireless adapter and bring up the ethernet adapter.
That will force the system to switch to the available network.
NOTE: The above command requires sudo or root privileges with the net-tools package installed.
Start by using the command:
The command above should list the default gateways available in the system, including the default interface.
An example output is as shown:
169.254.0.0/16 dev wlan0 scope link metric 1000
192.168.0.0/24 dev wlan0 proto kernel scope link src 192.168.0.10 metric 100
As we can see from the output above, the default interface is set to wlan0. However, we can change this by following a few steps.
Start by removing all the default interfaces with the command:
The command should remove all the default gateways. You can verify by running the ip list command:
An example output:
192.168.0.0/24 dev wlan0 proto kernel scope link src 192.168.0.10 metric 100
We can now proceed to add a default interface using the ip route command.
NOTE: Ensure to replace the IP address of the interface with your desired one.
Once executed successfully, the command should add the interface eth0 is the default.
We can verify this by running the ip route command:
default via 192.168.0.2 dev eth0
169.254.0.0/16 dev eth0 scope link metric 1000
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.10 metric 100
The output shows that the default interface is set to eth0 with our specified IP address.
Conclusion
That’s it for this one. In this article, we discussed how to change your default interface in Linux in two primary methods.
Thanks for reading!!