In this video, I'd like to walk you through setting up a stub and/or a totally
stub area.
So by default, area 2 and area 1 are normal areas.
We're not doing any kind of special filtering at the ABRs.
But if we made area 2 a stub area, very similar to what we did with IPv4,
if we make it a stub area, if there's routes that are being redistributed into
OSPF,
for example, from a static route or from BGP or from some other routing source,
and we're putting them into OSPF B3, those LSA type 5s and the corresponding L WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and we're putting them into OSPF B3, those LSA type 5s and the corresponding L
SA type 4s
and say how to get to the ASBR, those are going to be filtered and not
advertised into that stub area.
And to help compensate for that, the router is also going to advertise an LSA
type 3 of a default route.
Or I guess in IPv6, it's going to look like this, the default route.
So that way, the router is in area 2. We'll still have a path to forward to to
reach those redistributed routes.
And that would be an example of area 2 being a stub area.
Now if we want to make it a totally stub area, the syntax is identical on all
the routers in this area, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
the routers in this area,
except for on the area border router, which we're simply going to add on the
option of no summary.
And that will prevent the LSA type 3s for the 12 subnet and 13 subnet and 34
subnet, etc,
from being forwarded into this area.
So to reinforce this, we'll take a look at the routes here on our 8th first,
and then we'll go ahead and set up the area as a stub,
and then we'll proceed to make it totally stubby as well.
So here on router 8, let's go ahead and do a show IPv6 route for our center.
And let's go ahead and do that again and just look at the OSPF learned routes. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And let's go ahead and do that again and just look at the OSPF learned routes.
Fantastic.
And if we had a redistributed route, in fact, let's make one.
Let's go ahead up to our one, and it's going to create a static route for IPv6,
and we'll redistribute that into OSPF.
So here on router 1, let's do a config D, and we'll create a static route, IPv6
route.
Let's make something really obvious.
How about 2001 colon, DB8 colon, 678, 3 colon, how about 4 ones, colon colon,
flash,
and say 64 base, and then let's send that to null zero. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and say 64 base, and then let's send that to null zero.
All right, so we have a static route, and what we'll do is we'll redistribute
that into OSPF.
So we can do that by going into router, OSPF V3, process ID1,
and let's do a show, run, section router, see what we're working with here.
Then we'll go into address family for IPv6 unit cast, so we'll go ahead and
copy paste that.
And now within the address family, we'll type in redistribute space question
mark,
and let's redistribute static space question mark.
And then we can specify a metric if we wanted to, or we can just press enter.
I'm going to go ahead and just press enter.
And now if we exit out and do a show, IPv6 protocols, press enter, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And now if we exit out and do a show, IPv6 protocols, press enter,
it's now showing us that we are doing redistribution of static routes into OSPF
.
And if we went down to R8, let's make a road trip down there,
and hit the up arrow key for showing IPv6 routes, learn via OSPF, and press
enter.
And then space bar, there's the route right there numerically sorted, so it's
at the very end.
So it's our 1111 subnet.
And that's showing up as an external type to OSPF route.
And the reason for that is it's an LSA type 5 that R1 is adding into area 0 for WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And the reason for that is it's an LSA type 5 that R1 is adding into area 0 for
that network.
And also the area border routers are going to forward that down to their normal
areas.
So this is a result of an LSA type 5, the AS external type LSA.
That's being injected into area 0, and area border router R4 is forwarding that
down into
area 2, which is a normal area and that's why it's forwarding it.
But once it's a stub, this route should disappear.
Also if we scroll up here, you'll notice we don't currently have a default
route.
But that also will change once we make area 2, a stub area. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
But that also will change once we make area 2, a stub area.
So to configure this, because the configuration is virtually identical on all
routers except
for our four, I'm going to use this option up here.
It's a little carriage return symbol, and that way we can type in some commands
and send it to all of our routers at the same exact moment.
So we want to send this to our 8, our 6, and our 4.
That's our three routers that are participating in area 2.
And the command we want to send is config T to go into configuration mode.
We're going to go into router configuration mode or OSPF version 3, process ID1 WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
We're going to go into router configuration mode or OSPF version 3, process ID1
, and all
three routers.
Then we're going to say area 2, space, stub.
And that's going to be the same for all three routers and then we'll type in
end.
And let's go ahead and send that to our 4, our 6, and our 8.
We'll click here on send script and it is done.
So a moment ago, we had this external route for the 1111 subnet.
But now if we hit the up arrow key a couple times and do a show IPv6 route
again for OSPF
learned routes in its space, we have absolutely nothing.
And that's because I think we haven't fully converged yet. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And that's because I think we haven't fully converged yet.
So let me give that just a moment.
We'll hit the up arrow key, show IPv6 route, OSPF press enter, and that looks a
lot better.
We'll put the space bar.
And we can see here at the tail end that we no longer have that 1111 subnet.
But also because we're now stub area, we do have a default route that's been
injected into
the area by the ABR.
And if we want to further limit the LSA type 3s for these networks like the one
network
and the two network and the 34 network and so forth and so on, what we can do
is we can
tell the ABR. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
tell the ABR.
In this case, it's going to be R4 acting as the ABR.
We can specify the area 2 is not only a stub, but we can also issue the option
of no dash
summary, which will prevent all those detailed LSA type 3s from going into area
2.
It'll still sound the default route, which literally is a LSA type 3.
But all the other detailed LSA type 3s, it will prevent from going into area 2.
So to do that, we'll go back to R4.
Let's do a quick show run, section router.
And then we'll go into configuration mode.
And then we'll go further into router configuration mode for OSPF version 3, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
And then we'll go further into router configuration mode for OSPF version 3,
process ID1 by putting
that in.
Again, we're going to use this command area 2 stub, but we're going to add on
one additional
parameter and that is no summary.
Don't bother sending the LSA type 3s into that stub area.
So we'll say no dash summary, press enter, and we are done.
So now we have just created a totally stubby area regarding area 2.
So if we go back down to R8, which a moment ago, had all these inter-area
routes, now we'll
hit the up arrow key into a show IPv6 route OSPF and press enter. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
hit the up arrow key into a show IPv6 route OSPF and press enter.
Now we have the default route, courtesy of our ABR, and we have our intrat area
route.
That's the 46 subnet, but all the other inter-area routes, those summaries,
have been suppressed
by the area border router.
So can we still ping across the network?
Let's go to R7.
So R7, let's go ahead and try to reach this IP address that's on the gig 0 zero
of R7.
So back to R8, with that copied, we'll do a trace, space, and we'll paste in WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
So back to R8, with that copied, we'll do a trace, space, and we'll paste in
that destination.
And sure enough, we still have full connectivity, because we're using our H
using the default
route, our six, we'll also be using the default route.
And then our four has direct knowledge of that network, so it's going to
forward over
its optimal path to get down to area one, and all the routers in the path are
40 until
finally hits R7, and then finally R7 response.
So that my friends is how we can configure with OSPF version three, a stub or a
totally
stubby area, and we've also demonstrated what routes and LSA types are being WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
stubby area, and we've also demonstrated what routes and LSA types are being
filtered
as a result of a stub, or in this case a totally stubby area.
And just like in OSPF for IPv4, if we want to add our area border routers with
IPv6, we
can also do summaries to summarize a group of addresses and only advertise a
summary.
In the next video, I'll walk you through that one as well.