So currently we have our gateway A
and gateway B with a couple of VMs
connected to each of those segments they're supporting.
And right now, clients over here on Segment 10
cannot communicate with devices over here on Segment 20
because we have no connection between
gateway A and gateway B.
So to solve that, we're gonna add our third router,
our third gateway right here.
There'll be a tier zero gateway
that we can link to both gateway A and gateway B.
And based on our plan
it's gonna be this, the green router right here.
So we'll name it our tier zero gateway zero, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So we'll name it our tier zero gateway zero,
and then we'll go ahead and connect it
to both the tier one gateway A and tier one gateway B.
And when we do that, it'll automagically
use this address space of 10.64, something
to go ahead and create an auto assigned IP addresses
for the communication between tier zero
and these two tier one gateways.
So let's go to the N-S-X-C-L-I
and let's create our brand new tier zero, gateway zero.
So here with the networking tab selected,
we'll leave our network topology view
and click here on tier zero gateways. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and click here on tier zero gateways.
So at the moment, we don't have any
but it's super easy to create one,
we'll simply click here on add gateway,
then we'll specify the type of gateway we're creating
a tier zero, select that,
and then we'll give it a name.
So let's call it, our tier zero, space gateway, dash zero.
And the benefit of adding the "our" in front of it
is just that every time you see these gateways,
these logical gateways, you're gonna know
these are the gateways that we created
because we put an "our" in front of it.
So when we setup our tier zero gateway,
we have a choice of choosing active, active WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
we have a choice of choosing active, active
for fault tolerance or active standby.
And when we specify either active, active
or active standby, it's also going to require us to specify,
hey, for that fault tolerant feature and high availability,
which edge nodes do you wanna use?
And so we have our two edge nodes in a cluster
called "Our Edge Cluster" that can provide those services.
And that's all we need to specify right here.
So we've now created our tier zero, gateway zero.
So if we scroll down, we'll click on save.
And now that it's created,
it's giving us a further option to click on,
"Yes", we wanna do further configuration like, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
"Yes", we wanna do further configuration like,
specify additional details, for example,
routing information or specifying interface and so forth.
So for now, I gonna click on "No."
So we have our tier zero gateway zero.
It's not currently connected
to any tier one gateways at the moment.
And we also don't have any link segments.
So effectively we've got this router
gateway zero that's sitting up there in space.
We can verify that by going back
to the network topology tab here.
And there it is, right there.
So tier zero, gateway zero,
it has a gateway firewall rule in place as a service. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
it has a gateway firewall rule in place as a service.
However, we have no connectivity whatsoever yet
to gateway A or gateway B,
which are our tier one gateways.
So what we wanna do is link them together
so that linking together would look like this.
We wanna go ahead and do a connection here
and a connection here.
And as I mentioned, once we do that,
it'll automatically be using the address base of 100.64
and then some extension to that for those segments.
So we'll have a logical IP subnet here,
another logical IP subnet here
between our tier zero gateway and our tier one gateways. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
between our tier zero gateway and our tier one gateways.
So let's go ahead and associate or link
the tier zero gateway of gateway zero
to both these tier one gateways.
Now one question might be,
well, how do we go about doing that?
Do we go to the gateway zero
and tell it, we're linking it to gateway A and gateway B?
Or do we go to the, gateway A and B
and tell it that we're linking up to gateway zero?
And the way we do this is from the tier one gateways.
So we go to the properties of each of our tier one gateways
and say, "Hey, we want you to have as a connection,
a link to the tier zero."
So with networking on the top selected
and under connectivity,
we're gonna click on tier one gateways. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
we're gonna click on tier one gateways.
And currently here where it shows linked tier zero gateways,
not set, not set.
However, now that we do have a tier zero gateway to link to,
we can simply modify the properties of our tier one gateways
and tell them we wanna automatically link up
to our tier zero gateway.
So we'll start with gateway A first,
we'll click on the three dots,
and then from the menu, click on edit.
And then here where it says linked tier zero gateway,
we'll use the dropdown.
And because we now have a tier zero gateway,
we'll simply select it and boom,
now we have our connectivity from tier zero to tier one.
So if we scroll down, click on close editing. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So if we scroll down, click on close editing.
Then if we collapse this.
Notice now under linked tier zero gateway,
It's now showing us the tier zero gateway
that we are linked to.
And if we click on network topology, once again,
it should reflect that as well.
So here's our connectivity.
Let me make that full screen
and make that a little bit bigger.
There we go. So there's our connectivity
from our tier zero gateway zero over to gateway A.
And also what is interesting to note is
that it's using a slash 31.
So I teach a lot of the fundamentals of IP addressing WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So I teach a lot of the fundamentals of IP addressing
and subnetting and so forth, and I love it.
But at the entry level, we tell people, you know what,
you can't have any host addresses
that are all ones or all zeros.
And so really when you use the slash 30,
and then within that you're gonna have, for example,
in the first subnet, usable addresses of one and two.
And that'd be for example, zero in the last octet.
And then if you had, for example, a subnet ending in four
with a slash 30, the valid addresses on
that subnet subnet four would be dot five and dot six.
And then on the next subnet eight,
the valid addresses on a slash 30 would be nine and 10. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
the valid addresses on a slash 30 would be nine and 10.
And if you want more detail and training on subnetting
and variable link subnetting,
you can check out our CCNA course here at CBT Nuggets.
That course has some really rated sections, plural,
on IP subnetting including variable length subnet masking,
and also our CompTIA Network+
has information there as well
regarding how to do and implement IP subnetting.
So again, generally we're not gonna go past a slash 30
as we teach the entry level stuff.
However, there are some exceptions based on the vendor.
And here's one of them, where we're using a slash 31.
And then we can actually literally have this address, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And then we can actually literally have this address,
100.64.0.0 on one end of that connection
and the address of 100.64.0.1 at the other end
using a slash 31.
So that's what it's done right here for us.
And if we wanna control that address base
and not use that specific range,
we can do so by going to the properties here
of our tier zero gateway
and simply telling it what addressing space we wanna use.
So I'm gonna go ahead and take this out of full screen
and let's go back to the tier zero
gateway just for a moment.
And if we look at the details here, in fact, I'll go ahead WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And if we look at the details here, in fact, I'll go ahead
and click on the three dots to edit it.
From the menu, select edit.
And then here on additional settings
for our tier zero gateway,
here's where we can specify
the addressing that we wanna use.
So right here where it specifies the
T-zero to T-one transit, it's automatically using
that 164 address space.
And so we could go ahead and choose
to put in a different range there if we wanted to.
However, for now we can take that default.
I just want you to be aware of where
that IP addressing space is coming from
and it is a default that's in place.
All right, so back to network topology, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
All right, so back to network topology,
I'm gonna click on, "Yes",
I don't wanna change anything there on the T-zero.
So next, let's add another link between gateway B
and the gateway zero, the T-zero gateway, zero router.
And when we do that, it's very likely to go ahead
and use the next two IP addresses,
which would be 100.64.0.2
and three respectively with a slash 31.
Again, that's being done automatically by the system.
So let's go to our tier one gateway
and we'll go to tier one gateway B, click on the three dots,
click on edit from the menu,
and then select the tier zero gateway like that.
And then click on save. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And then click on save.
And then we'll go ahead and scroll down.
We'll click on close editing.
So now we can see we have our tier one gateways A and B
both connected to gateway zero,
which is a tier zero gateway.
And here it says in progress.
So if we click on the refresh button there,
just wanna confirm that it's done.
All right, that looks great.
So if we go back to our network topology
and if we expand that a little bit,
so there's our second connection now between the gateway B
and the tier zero router.
And here are the IP address that it's using
for each end of those connections.
So these are two different subnets logically WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So these are two different subnets logically
between the tier zero gateway and gateway A
and the tier zero gateway and gateway B.
So let me zoom out a little bit here.
So if we took these PCs here, that are connect,
these little VMs that are connected to these segments,
they still don't have the ability to reach each other.
And the reason for that is
that even though we now have these three gateways,
this tier zero gateway has no knowledge about the
10 10 network down here behind gateway A
and also doesn't have any knowledge about the routes
down here to 10 20, which is behind gateway B.
And also to verify that
and also not to reinforce WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and also not to reinforce
that all of our transport nodes have
all three of these distributed routers.
Let's for a moment go back to the command line.
So here at both of our edges,
let's go ahead and do a get gateways and press enter.
And here are the three right here.
So we have gateway A, B, and also gateway zero.
And those same three distributed routers exist
on both of our edges.
And if we also looked at our host transport nodes,
they would also have these three distributed routers
and all the information regarding them.
So if we were gonna take a look at the routing table
on gateway zero, because it's in VRF four WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
on gateway zero, because it's in VRF four
as shown right here.
The easiest way to work with and look at the details
for that specific virtual router
is to go ahead and simply go into VRF mode, for VRF four.
And to do that, we'll type in "VRF 4", press enter.
You'll notice the prompt changes to help us remember
that we are now in VRF four.
And then from here we can do commands like, get forwarding.
So that command right here in VRF four
is showing us the IP routing table.
So also it's showing us down below,
it's showing us the IPV6 as well.
We're gonna focus our attention here
for the moment on IPV4. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
for the moment on IPV4.
So notice that this logical router,
our tier zero, gateway zero router,
it knows about the directly connected networks of 100.64.0.0
and 100.64.0.2,
and it has IP addresses on those specific subnets.
And those are the interlinks between itself, gateway zero
and gateway A and gateway B, both as tier one routers.
However, what it does not know about yet,
it doesn't know anything about how
to forward packets in the direction of 10 10 or 10 20. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
to forward packets in the direction of 10 10 or 10 20.
So to solve that, we're gonna go back to our game plan
and implement this step right here,
which is telling our tier one gateways,
gateway A and gateway B, that they both need to advertise
their directly connected networks.
And when we tell 'em to advertise their
directly connected networks,
they'll then start advertising the 10 10 network,
or at least gateway A will, up to the tier zero router.
So the 10 10 network will be in the routing table.
And when we tell gateway B to advertise
its directly connected networks
that will cause gateway zero to then learn
about how to forward in the direction of 10 20 as well. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
about how to forward in the direction of 10 20 as well.
So in the next step, let's train these two tier one routers
to advertise their directly connected subnets.
So I'll see you in the next video for exactly that.