Now what is in a V in a V or network functions virtualization is the idea that you virtualize and network
devices and network functions.
Here's a document explaining in a V.
And it's very good if you're interested in getting into the details.
This is from the SD and an open floor World Congress in 2012.
But you don't need to spend a lot of time going through this document.
That's only of interest.
I'll explain briefly what NFC is for the CCMA exam servers have been virtualize for years so as an example
here I'm running a Cisco call manager
as a virtual machine in yes exciting and I can connect to that server as an example using a web browser
and then configure the server servers are now virtualizing in the cloud and I can spin up instances
of servers very very quickly using Amazon easy to or Microsoft Azure or the Google cloud networking
however has generally in the past sold physical boxes for functions.
So in other words if you wanted a firewall you would buy a physical piece of hardware that provides
a function or a set of functions to you.
In this case firewall ing if you wanted a VPN device in the past you would buy a VPN concentrator or
a device dedicated to creating VPN connections in the past.
If you wanted a load balancer you would buy a physical load balancer or a session border controller
you would buy a physical device for that function rudders such as a p rather of physical devices.
If you want a router you would buy a physical rudder.
Now the idea with network virtualization is we virtualize network devices in the same way that we virtualize
servers.
So we take these physical devices and we run them as virtual appliances on physical servers.
And here's an example once again of doing that.
I've got a single physical server running iOS 6 I bet here I've got multiple Cisco CSR routers running
as virtual machines in iOS 6 I use the Come on show IPO SPF neighbor notice I see multiple neighbor
relationships.
So this device 1 9 2 1 6 8 1 2 or 3 is a physical router.
So what I'll do is Telnet to that physical Rada and I'll log in.
Notice this is in 1841 so show version shows me that this is in 1841 physical Rada showed dialogue as
an example shows me the physical components in that Rada but back on the E6 I rather show version shows
me that this is a all Rada showed Di eg
doesn't show the same information
because this is a virtual router not a physical Rada you can see as an example that it's a CSR 1000
V so show IPO SPF neighbour once again shows me different neighbour relationships and I could Telnet
to a another Roorda
this Rada is a 1941.
So this is another physical rather.
So what's the point rather than running physical Rodders.
Why not run multiple virtual routers in the same way that you run the virtual service the concept of
having a physical device for every function doesn't make sense in today's world as I demonstrated.
It only takes a few minutes to spin up a virtual machine on Amazon it's been easy in the past to spin
up virtual servers and allocate a virtual disk space or storage but one of the big problems in the past
has been that networking required physical devices so just like years ago server administrators no longer
have a physical server per application such as e-mail or Web services.
We know in networking don't have a physical device for a physical function we can run virtual routers
and virtual firewalls as virtual machines alongside our virtual servers one of the advantages of doing
that as an example is you could run a virtual firewall in front of every virtual server if you needed
to.
You can implement what's called micro segmentation where you segmented your network down into tiny subnets
or tiny segments to reduce broadcasts to implement better security and other benefits.
It doesn't make sense today to have a physical network device for every function.
If you have the requirement for a firewall it doesn't make sense to buy a physical firewall for your
virtual servers.
In some cases it makes sense to buy a virtual firewall that you run on the same hypervisor as your virtual
service.
So this is the idea of network function virtualization.
We firstly virtualize an appliance such as a rider or a firewall or a load balancer but then taking
it a step further.
We can also load balance functions.
So if all you need is to implement something such as VR or LP or H.S. or P It doesn't make sense to
run a full operating system in the server world.
We have the concept of Docker and the same kind of ideas now starting to happen in networking where
we just run functions rather than entire operating systems.
I've added some videos about Docker to the course.
They are only of interest and are not part of the CCMA exam.
So if you're interested in learning some real world stuff about Docker and newer technologies have a
look at those videos.