In this video, I want to give you a quick overview of networking in virtualization.
Let's say that here we have your virtualization host.
On this virtualization host, you have your network.
Let's call it ETH0 for simplicity's sake, and ETH0 is connected to the network.
And along the virtual host, we have these different virtual machines.
And let's say they are here, VM1, VM2, VM3, and so on.
How are they going to get networked?
Well, that is by using the virtual bridge.
You normally have a virtual bridge device.
There are different ways how this virtual bridge can be implemented, by the way.
There is also OpenVSwitch as a virtual bridge on steroids, but that doesn't change the idea.
What is going to happen is that the virtual bridge connects the ETH0, and the ETH0 network
card in your virtual machines, well, that is going to connect to the virtual bridge.
And that makes it all these virtual machines can connect to one another.
And as this virtual bridge is implementing network address translation technology, it
also means that your virtual machines can go out.
Now, it's even going to be more interesting if there is another virtual host.
Let me draw it real small.
In this other virtual host, you might want to have some virtual machines as well.
And these virtual machines might be between a virtual bridge also.
Now, what are you going to do to make sure that you have one big network between the
virtual bridges on all these hosts?
Well, that is where SDN is coming in, software-defined networking.
Goes a little bit far for standalone virtualization, but if you create a virtualized data center,
it's really important to join all these virtual bridges together in one software-defined network
so that the virtual machines think that they're all on the same network.
So virtual networking is all about the virtual bridge.
You want to see it?
Use IPA.
And there we can see VRBR, VRBR0, and VRBR0, that is my virtual bridge.
It has an INET interface, which creates the internal network for the virtual machines.
And this bridge makes that through the regular ENS33, my virtual machines can go outside.