So when we left off, we verify that we have some OSPF
neighborhoodships to verify that we could expand our tier
zero gateway, go down to OSPF, expand that, and then click
on the hyperlink view right next to OSPF neighbors.
Just to verify we have our OSPF neighbors in place.
So here are the OSPF neighbors from the perspective of
gateway zero and is two respective edge nodes that are
supporting it.
However, what we haven't done yet is told the external world,
the external routers to share information with the edge
nodes and we haven't told the gateway zero via its edge WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
nodes and we haven't told the gateway zero via its edge
nodes to share information with the external routers.
So to train the tier zero gateway to start advertising routes,
we can go ahead and click on the three dots, then click on
edit and then scroll down below the OSPF section.
We have a section here for route redistribution.
So on this T zero gateway, we currently have routes for the
1010 zero network.
We're learning those via gateway A, we also have routes for the
1020 network.
We're learning those via gateway B.
And what we can do is we can redistribute those into OSPF.
And that way our external OSPF buddies, for example, the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And that way our external OSPF buddies, for example, the
40 gate at dot one and the multi layer switch at dot
136, they can both now start learning about those routes.
So here under the route redistribution section, I'm going to
go ahead and first of all, click on via OSPF.
I'm going to go ahead and say yes and click on save.
And then furthermore, I'm going to go ahead and go into route
redistribution and click on set.
So for the name, I'm going to give it a friendly name of
those class, seg 10 and seg 20 subnets.
And then for the destination, I don't want it to be BGP.
I want it to be OSPF. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
I want it to be OSPF.
And then for the actual route redistribution, we'll click here on set.
And we have two major sections.
We have routes directly related to our tier zero gateway.
And we also have routes related to our tier one subnet.
So if we wanted to take the tier one subnets, including the 1010
and 1020, we simply click this checkbox right there and boom.
That's going to do it for us.
So once we save this, this should cause the routes, the 1010 and
the 1020 subnet routes to be advertised via OSPF to our external routers.
In fact, before I click on apply, let's go take a look at the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
In fact, before I click on apply, let's go take a look at the
routing table on our multi-layer switch and verify that we don't yet
have routes for the 1010 network or the 1020 network.
And also before we head over to the top of rack switch.
And we also just confirm here that the tier zero gateway,
which we're currently looking at the routing table for,
it knows about how to reach the 1010 zero and 1020 zero.
However, if we minimize that and we go over to my multi-layer switch.
So this is our top of rack switch here.
And we do a show IP route press enter.
In fact, let me just go ahead and filter that a little bit and say, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
In fact, let me just go ahead and filter that a little bit and say,
please show me only output that includes a slash 24.
And that'll thin the output just a little bit fair enough.
So on this external router, this multi-layer switch running OSPF,
it does not yet know about how to reach the 1010 subnet or the 1020 subnet.
That's not in its routing table.
So back here in the ASX manager,
focusing on our tier zero gateway,
with the connected interfaces and segments now checked under advertised tier
one subnets,
let's click on apply.
And then we'll click on add and apply and save. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And then we'll click on add and apply and save.
And we'll just keep clicking.
Yes, yes, yes until it gives us a final acknowledgement that it's all done.
So if we click on collapse all, we are now good to go.
So just to check our work, we expand our tier zero gateway
and go into route redistribution.
We are doing route redistribution, the details.
If we click on the hyperlink, it'll show us the details
and we'll redistribute them into OSPF.
So now if we go back to the multi-layer switch,
which previously didn't have routes to the 1010 or 1020,
if we hit the upper key and do the same exact command again, check it out. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
if we hit the upper key and do the same exact command again, check it out.
Now we have dynamically learned via OSPF those two routes.
And if we want to forward packets to either of those destinations,
the 1010 zero anything or the 1020 zero anything,
we are going to be handing off to the next top at dot 61,
which in our topology is the active edge router at dot 61.
Well, edge two is acting currently as a standby.
So from here, we can do a ping, for example, to 10 dot 10 dot zero dot 10.
And that is the IP address of VM1, we'll press center
and we have connectivity there.
Also, while we're here on this multi-layer switch, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Also, while we're here on this multi-layer switch,
let me create a quick loopback interface interface.
We'll call it loopback nine.
And we'll give the IP address of 99 dot 99 dot 99 dot 99 dot 99.
And I'll go ahead and give that a 32-bit mask.
And then I'll also include it as part of OSPF.
So it's advertised IP OSPF one, and we'll put that
and we'll put this logical interface in area zero.
And then we'll exit out and do a show IP OSPF interface brief,
just to verify that that interface is now included as part of OSPF.
And as a result, because we're now advertising that in OSPF,
our tier zero gateway should automatically be learning about that network. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
our tier zero gateway should automatically be learning about that network.
So we can verify that by going back to edge one
and then typing in get gateways and then just going into the VRF
or services router here.
So that's VRF four and then it'll do a get route.
And sure enough, there's the OSPF learned route right there.
So from the tier zero gateway, we're in the VRF for it right now.
If we did a ping to 99 dot 99 dot 99 dot 99 dot 99.
And that should work because we have a route now to get there.
Also, if we brought up one of our little VMs, this is the VM10.
VM10 has a default gateway pointing to gateway B.
Gateway B has a default route that leads up to gateway zero WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Gateway B has a default route that leads up to gateway zero
and gateway zero, which we're currently looking at the routing table here for.
It has a route to that 99 99 99 with that next top of our multi-layer switch.
Which if we scroll up just a little bit, is it dot 136?
So that means this little VM should also be able to ping that address,
with type in ping 99 dot 99 dot 99 dot 99 press center and survey says,
no worries whatsoever.
So we'll go ahead and do a control C.
And the last thing I'd also like to do is I'd like to train
my external networked environment to advertise a default route. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
my external networked environment to advertise a default route.
So currently we have a statically learned default route
and it has an AD of 150.
So OSPF has an AD of 110.
So if we train my external network to advertise a default route via OSPF,
this top route right here, the default route should be replaced in the routing
table
with the route learned via OSPF.
And so the easiest way for me to do that right here is to do it from the multi-
layer switch,
which is currently participating in OSPF.
So let's do a config T.
In the Cisco world, that's how we go into configuration mode on this platform. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
In the Cisco world, that's how we go into configuration mode on this platform.
And then from here, we'll go into router OSPF, that same process ID number
and say default information originate and press enter.
What that says is, hey, dear Mr. Multi-layer Switch, if you have a default
route, which it does,
please go ahead and advertise that into OSPF.
And as a result, our tier zero gateway has now learned about a default route
with a better AD of 110.
And as a result, that should be the new default route in the routing table.
So I'll go ahead and bring that back down the size.
Let's go back to our edge device, make that full screen, and let's hit the app WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
Let's go back to our edge device, make that full screen, and let's hit the app
arrow key.
So a moment ago, when we looked at the routing table for gateway zero,
it showed the static route with the default route, which has an AD and
administrative distance of 150.
But because now we're advertising a default route and it's coming in via OSPF,
it has a better or lower AD if we press enter now with a get route.
So notice now that we still have a default route, but now it's being learned
via OSPF.
This is the route in our routing table for the gateway zero.
And that's because this route, learned via OSPF, has a lower and better
administrative distance
than our static route, which we set at 150. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
than our static route, which we set at 150.
So from a client's perspective, and this is my little VM right here,
we should be able to ping any of the addresses on the 192.1 state one network.
So we did a ping to 192.168.1.1.
That's working because my router at .1 also has the routing information on how
to forward back now
to 1010 and 1020, those subnets.
If we tried to ping 136, which is the interface on the MOCALAYER switch up
there, that works great.
And once again, if we tried to ping the loop back of 9999, that also works WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And once again, if we tried to ping the loop back of 9999, that also works
because we have routing
in both directions, meaning this client knows how to forward in the direction
of that network
and so does the entire infrastructure up to that point.
And then the target, in this case, the loopback interface on the MOCALAYER
switch
has routing information on how to route back down to the 1010 or 1020 subnets,
respectively.
So now that we've taken a look at the concepts and configuration and
verification of OSPF,
in the next section, I'd like to offer you a little challenge to help reinforce
our skills.