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In this video, I'd like to walk you through setting up a stub and/or a totally

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stub area.

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So by default, area 2 and area 1 are normal areas.

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We're not doing any kind of special filtering at the ABRs.

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But if we made area 2 a stub area, very similar to what we did with IPv4,

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if we make it a stub area, if there's routes that are being redistributed into

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OSPF,

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for example, from a static route or from BGP or from some other routing source,

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and we're putting them into OSPF B3, those LSA type 5s and the corresponding L
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and we're putting them into OSPF B3, those LSA type 5s and the corresponding L

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SA type 4s

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and say how to get to the ASBR, those are going to be filtered and not

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advertised into that stub area.

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And to help compensate for that, the router is also going to advertise an LSA

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type 3 of a default route.

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Or I guess in IPv6, it's going to look like this, the default route.

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So that way, the router is in area 2. We'll still have a path to forward to to

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reach those redistributed routes.

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And that would be an example of area 2 being a stub area.

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Now if we want to make it a totally stub area, the syntax is identical on all

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the routers in this area,
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the routers in this area,

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except for on the area border router, which we're simply going to add on the

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option of no summary.

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And that will prevent the LSA type 3s for the 12 subnet and 13 subnet and 34

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subnet, etc,

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from being forwarded into this area.

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So to reinforce this, we'll take a look at the routes here on our 8th first,

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and then we'll go ahead and set up the area as a stub,

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and then we'll proceed to make it totally stubby as well.

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So here on router 8, let's go ahead and do a show IPv6 route for our center.

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And let's go ahead and do that again and just look at the OSPF learned routes.
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And let's go ahead and do that again and just look at the OSPF learned routes.

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Fantastic.

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And if we had a redistributed route, in fact, let's make one.

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Let's go ahead up to our one, and it's going to create a static route for IPv6,

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and we'll redistribute that into OSPF.

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So here on router 1, let's do a config D, and we'll create a static route, IPv6

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route.

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Let's make something really obvious.

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How about 2001 colon, DB8 colon, 678, 3 colon, how about 4 ones, colon colon,

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flash,

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and say 64 base, and then let's send that to null zero.
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and say 64 base, and then let's send that to null zero.

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All right, so we have a static route, and what we'll do is we'll redistribute

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that into OSPF.

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So we can do that by going into router, OSPF V3, process ID1,

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and let's do a show, run, section router, see what we're working with here.

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Then we'll go into address family for IPv6 unit cast, so we'll go ahead and

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copy paste that.

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And now within the address family, we'll type in redistribute space question

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mark,

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and let's redistribute static space question mark.

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And then we can specify a metric if we wanted to, or we can just press enter.

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I'm going to go ahead and just press enter.

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And now if we exit out and do a show, IPv6 protocols, press enter,
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And now if we exit out and do a show, IPv6 protocols, press enter,

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it's now showing us that we are doing redistribution of static routes into OSPF

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.

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And if we went down to R8, let's make a road trip down there,

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and hit the up arrow key for showing IPv6 routes, learn via OSPF, and press

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enter.

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And then space bar, there's the route right there numerically sorted, so it's

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at the very end.

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So it's our 1111 subnet.

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And that's showing up as an external type to OSPF route.

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And the reason for that is it's an LSA type 5 that R1 is adding into area 0 for
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And the reason for that is it's an LSA type 5 that R1 is adding into area 0 for

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that network.

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And also the area border routers are going to forward that down to their normal

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areas.

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So this is a result of an LSA type 5, the AS external type LSA.

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That's being injected into area 0, and area border router R4 is forwarding that

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down into

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area 2, which is a normal area and that's why it's forwarding it.

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But once it's a stub, this route should disappear.

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Also if we scroll up here, you'll notice we don't currently have a default

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route.

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But that also will change once we make area 2, a stub area.
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But that also will change once we make area 2, a stub area.

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So to configure this, because the configuration is virtually identical on all

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routers except

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for our four, I'm going to use this option up here.

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It's a little carriage return symbol, and that way we can type in some commands

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and send it to all of our routers at the same exact moment.

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So we want to send this to our 8, our 6, and our 4.

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That's our three routers that are participating in area 2.

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And the command we want to send is config T to go into configuration mode.

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We're going to go into router configuration mode or OSPF version 3, process ID1
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We're going to go into router configuration mode or OSPF version 3, process ID1

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, and all

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three routers.

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Then we're going to say area 2, space, stub.

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And that's going to be the same for all three routers and then we'll type in

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end.

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And let's go ahead and send that to our 4, our 6, and our 8.

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We'll click here on send script and it is done.

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So a moment ago, we had this external route for the 1111 subnet.

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But now if we hit the up arrow key a couple times and do a show IPv6 route

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again for OSPF

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learned routes in its space, we have absolutely nothing.

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And that's because I think we haven't fully converged yet.
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And that's because I think we haven't fully converged yet.

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So let me give that just a moment.

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We'll hit the up arrow key, show IPv6 route, OSPF press enter, and that looks a

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lot better.

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We'll put the space bar.

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And we can see here at the tail end that we no longer have that 1111 subnet.

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But also because we're now stub area, we do have a default route that's been

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injected into

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the area by the ABR.

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And if we want to further limit the LSA type 3s for these networks like the one

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network

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and the two network and the 34 network and so forth and so on, what we can do

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is we can

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tell the ABR.
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tell the ABR.

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In this case, it's going to be R4 acting as the ABR.

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We can specify the area 2 is not only a stub, but we can also issue the option

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of no dash

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summary, which will prevent all those detailed LSA type 3s from going into area

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2.

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It'll still sound the default route, which literally is a LSA type 3.

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But all the other detailed LSA type 3s, it will prevent from going into area 2.

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So to do that, we'll go back to R4.

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Let's do a quick show run, section router.

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And then we'll go into configuration mode.

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And then we'll go further into router configuration mode for OSPF version 3,
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And then we'll go further into router configuration mode for OSPF version 3,

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process ID1 by putting

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that in.

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Again, we're going to use this command area 2 stub, but we're going to add on

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one additional

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parameter and that is no summary.

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Don't bother sending the LSA type 3s into that stub area.

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So we'll say no dash summary, press enter, and we are done.

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So now we have just created a totally stubby area regarding area 2.

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So if we go back down to R8, which a moment ago, had all these inter-area

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routes, now we'll

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hit the up arrow key into a show IPv6 route OSPF and press enter.
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hit the up arrow key into a show IPv6 route OSPF and press enter.

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Now we have the default route, courtesy of our ABR, and we have our intrat area

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route.

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That's the 46 subnet, but all the other inter-area routes, those summaries,

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have been suppressed

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by the area border router.

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So can we still ping across the network?

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Let's go to R7.

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So R7, let's go ahead and try to reach this IP address that's on the gig 0 zero

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of R7.

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So back to R8, with that copied, we'll do a trace, space, and we'll paste in
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So back to R8, with that copied, we'll do a trace, space, and we'll paste in

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that destination.

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And sure enough, we still have full connectivity, because we're using our H

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using the default

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route, our six, we'll also be using the default route.

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And then our four has direct knowledge of that network, so it's going to

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forward over

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its optimal path to get down to area one, and all the routers in the path are

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40 until

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finally hits R7, and then finally R7 response.

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So that my friends is how we can configure with OSPF version three, a stub or a

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totally

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stubby area, and we've also demonstrated what routes and LSA types are being
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stubby area, and we've also demonstrated what routes and LSA types are being

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filtered

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as a result of a stub, or in this case a totally stubby area.

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And just like in OSPF for IPv4, if we want to add our area border routers with

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IPv6, we

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can also do summaries to summarize a group of addresses and only advertise a

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summary.

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In the next video, I'll walk you through that one as well.