Having a technical solution for a problem is a great thing.
And in this video, I'd like to chat with you about some
of the challenges and problems that service providers had
to overcome and why MPLS layer 3 VPNs do exactly that.
[MUSIC PLAYING]
So let's play the role, you and I,
of service provider for a minute.
And so we're going to say this is our cloud.
This is our-- well, this represents our service provider
network.
And you know, what keeps a good service provider going is WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And you know, what keeps a good service provider going is
customers, paying customers.
And so in this topology here, let's imagine
we have two customers.
So we've got this customer here, which
I'm going to affectionately call Customer 1.
And this is their site, their geographic location, number 1.
And over here, we have Customer 1, same customer--
again, they're both green there--
but this is their second site.
And we also have Customer 2 and their site
1 down here, and Customer 2 down the right, and their site 2.
So if we're a really good service provider,
here's what's going to happen. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
here's what's going to happen.
And I'll go ahead and use a different color here.
Let's imagine we have all these routes that
are at Customer 1, site 1.
So we'll call it C1 site 1 routes.
And we want to communicate those routes to make
sure those routes are available over here
at customer 1, site 2.
So we want to basically advertise those routes
so that the site 2 can reach all those customer
site 1 routes and vise versa.
If we've got routes over here, then we use black.
We have a whole bunch of routes over here at customer site 2, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
We have a whole bunch of routes over here at customer site 2,
and we want those to be advertised and reachable
by the devices over here at site 1.
So basically, we want to make sure
that we have reachability between the two sites.
The customer is paying for us, right?
That's what they want out of it.
We want those routes to show up, and if we have a user like Bob
over here at site 1 who sends a packet to, let's say--
we'll say server 2 here--
he sends a packet over to server 2.
We want to make sure that packet--
what's the word I'm looking for here? WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
what's the word I'm looking for here?
Reaches that server, which implies that not only does
this site have reachability or the routes
to get to the server and networks over here,
but also, when they send the packet,
the actual data plane works, meaning
the service provider can receive the packet,
forward it over, and get it to their site.
Now, if we only had one customer and two sites,
it wouldn't be too tough to just get basic connectivity
from site to site.
However, as a service provider, if we
have a second customer or a third customer
and a fourth customer or hundreds or thousands WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and a fourth customer or hundreds or thousands
of customers, we need to have that same kind
of functionality of connectivity and the routes
for each one of them.
So let me go ahead and use green here.
So all the routes for a customer on one of their sites
need to show up at their respective sites,
and we'll get purple here for Customer 2.
So all the routes for Customer 2 need to show up
at their respective locations.
And when traffic is being sent, we
need to be sure that traffic goes through.
Now, here's the challenge.
What we don't want to do is we don't WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
What we don't want to do is we don't
want to accidentally take routes from customer 1
and advertise them down to customer 2 or vise versa.
So the routing has to be correct,
and we also have to make sure that the transit or the traffic
goes correct.
So that's where MPLS layer 3 VPNs come into play.
When I first-- this is over a decade ago,
maybe 15 years ago when I first started learning about MPLS
layer 3 VPNs.
I had-- let me bring up the big screen for this.
When I thought of VPNs, I thought of, oh, OK, IPSec. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
When I thought of VPNs, I thought of, oh, OK, IPSec.
Back in the day, IPSec was the name of the game there.
There's a lot of other types of cryptographic VPNs these days.
But I was thinking, VPNs, site-site VPNs.
Well, in the context of MPLS layer
3 VPNs, what we're referring to are specific routes
for a specific purpose.
Let's imagine Customer 1.
All their routes from site 1 and site 2,
all those routes we could put logically in this container
called a VPN for that customer.
So in the context of MPLS layer 3 VPNs, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So in the context of MPLS layer 3 VPNs,
let's tweak our brains a little bit and say,
well, if we ever talk about VPNs,
we're talking about a group of routes for a specific purpose.
So Customer 2 is going to have a group of routes in their VPN,
and Customer 1 is going to have a group of routes
in their VPNs.
And guess what?
We don't want to-- well, there are
times when we might want to share routes
between two different VPNs.
However, the plain Jane layer 3 VPNs--
we want to keep customer 1's VPN routes, their group of routes,
separate from customer 2 and customer 3 and so forth. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
separate from customer 2 and customer 3 and so forth.
So that's what the concept of VPN
is referring to in the world of MPLS layer 3 VPNs.
It's a certain group of routes that we
want to control where those routes are shared.
And then as packets get sent into the network,
we also want to make sure that traffic is forwarded correctly
to the correct endpoint.
So that's the concept of MPLS layer 3 VPNs.
And now, to pull this off, it is actually
pretty simple from the customer's perspective.
All they do is they peer with their provider WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
All they do is they peer with their provider
and all the routes show up.
Yay!
But in the service provider network,
there is a laundry list of technologies and techniques
that we are going to use as a service provider
to implement this layer 3 VPN solution for each
of our customers.
So in the next video, here's what I'd like to do.
I'd like to provide a fairly concise list of some
of the technologies that we're going to be using.
And then as we continue on in these videos,
we'll break each one of those down,
show you the details of them, and we'll WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
show you the details of them, and we'll
build to a fully functional layer 3 VPN
network for customer 1 and customer 2
by the time these videos are completely done.
All right.
So I'm excited.
I'll see you in the next video, where
we'll take a look at the techniques
and technologies used in the service provider network.
Meanwhile, I hope this has been informative for you,
and I'd like to thank you for viewing.