If you have ever plugged a network cable into a computer, you are familiar with what a physical network interface is like.
Sometimes, it's useful to create "virtual" network interfaces. For example, if you are running multiple virtual servers on a single computer, each virtual server will need a virtual network interface in order to communicate with the network.
You can see a list of all your existing network interfaces with the ip link command:
Depending on how your computer is configured, you will usually see:
- lo: this is the "loopback" adaptor - it's a virtual network interface that is automatically enabled on all computers.
- eth0: this adaptor typically refers to your ethernet card - that you plug a network cable into for network access.
- wlan0: this adaptor typically refers to your wireless access card
To add a new virtual network interface, type (replace "jamie" with your username):
sudo ip tuntap add dev tap0 mode tap user jamie
And you should see your device.
Before you can use it, you will need to set the state to UP.
sudo ip link set tap0 up
After re-running ip link, you may notice that it still says: "state DOWN"
That's because it's not yet in use.