[AUDIO LOGO]
So next, let's jump in and look at our new type
8 and type 9 LSAs.
Now, as we go through, we'll talk about what the type
8 and type 9 are actually for--
however, when we get into the command line
to look at these in the database,
we'll actually go ahead and take a look at the differences
in the other LSA types as well.
So that's what our goal is going to be in this video.
Let's jump in and start talking about those new type
8 and type 9 LSAs and what they're actually for.
So as we mentioned, one of our new LSA types is the type 8.
Now, the type 8 is actually a very interesting LSA type.
The reason for that is it carries link local information.
The key word here being local.
We're going to see how this affects things
in just a moment, but keep in mind
that this is local information for a router.
Now, these are called link LSAs, just from a naming convention
perspective.
Now, the reason we need these is as we mentioned
in our previous video, everything in IPv6
uses link local addressing.
If we're going to be using link local addresses as our next hop
and things like this in our routing, well, then clearly,
we have to know the link local addresses of our neighbors.
Now, the interesting part here is since it's, again, local
it only includes directly connected neighbors.
Now, this definitely brings up an interesting situation,
what situation?
Well, doesn't that mean that the type 8 is, in fact, breaking
the normal OSPF rule that databases must match.
How can these databases match?
If they only include connected information.
Every router is going to be connected
to different neighbors.
Therefore, every router will have different type 8 LSAs
in its database.
Therefore, the databases cannot match.
Now, just so we're very clear here,
the type 8 is the exception to the rule, OK?
Generally speaking, yes, the database
is still have to match for all of our other LSA types.
It's fun to point out that it's breaking the rule,
but at the end of the day, it's breaking the rule
because that's what's needed here.
But the rest of OSPF, again, still works
as normal and every router in the area
must have the same matching database.
So yes, it's an exception, but we're not fundamentally
changing that rule in OSPF version 3.
Now, the type 9 LSAs are used to carry the prefixes that are
available on each router ID.
Remember that the type 1s and type 2s in OSPF version
3 only carry topology information.
That would be what router ID is connected to what router ID.
So for example, maybe we have a couple of routers here.
They're, of course, connected together in some fashion.
And we'll just say for the sake of argument
and to keep it simple, maybe this is router ID 1.1.1.1,
this one is 2.2.2.2, and this one is 3.3.3.3.
We'll just keep it simple.
Well, again through the type 1 and type 2 LSAs,
we're going to learn which router IDs are connected
to which other router IDs.
So what I just sort of drew here would
be what we would learn from the type 1s and type 2s.
What the type 9 is going to tell us is, oh, by the way,
3.3.3.3 over here has the prefixes 2001:DB8:3::3/64
and maybe it has a 2001:DB8:100::3/128,
maybe that's its loopback address.
But what we're doing with the type
9 LSAs is we are mapping these prefixes to this router ID.
Those two pieces of information together
allow us to fill out our routing tables
to know which prefixes are available through which
router ID.
And again, simply from a naming perspective,
these are called intra-area prefix LSAs
because they're dealing with the prefixes inside of an area.
So just like type 1s and type 2s,
these will not go into other OSPF areas.
So let's go ahead and clean that up a little bit.
Just as a reminder here, remember
that the type has been renamed to inter -area.
This is, of course, the LSA that goes between areas,
and the type 4 has been renamed to inter-area router.
This, of course, is to advertise ASPRs in other areas.
We talked about this in the previous video.
This is just here as a reminder before we
take a look at the database.
One other thing to be aware of, OSPF version 3 does
have different options that will be on the various LSAs.
We don't need to sit here and go through every entry
on the table here.
I just put it here for your reference.
so as we're going through the database,
if you're not sure what one of these options are,
you can come back here and reference to this table
so you'll understand what it's for.
That said, let's take a look at our topology
real quick so we know which routers we're going to look at
and what's going on as far as what entries
we should see in our database.
So we'll be using OSPFv3 topology 1,
and the main thing we want to discuss here
is since we've not actually gotten to our configuration
yet in this skill, routers 6, 1, and 2 are not yet configured.
So what that really means as we go
through this video is as of right now,
we're only going to see information
on this part of the network down here at the bottom.
As such, we'll be looking at the database
mostly from the perspective of router 8
and a little bit on router 7.
But we will see some entries because we
do have some routers in area 100 and, of course,
some routers in our own area.
So let's go ahead and jump in and take a look
at the database.
So here on router 8, let's do a show OSPFv3 database.
And we'll start by looking at the type 1 LSAs.
So let's look at the router LSA.
We'll just scroll to the bottom here and pick on one.
The main thing we're trying to see here
is notice that it has entries such as the advertising router.
We can see that it's connected to another router
as a point-to-point link.
We see that neighboring router's router ID,
but notice there's no prefix.
There's no IPv6 prefix here.
This is just topology information.
What router is connected to what other router.
And of course, if we were to scroll through here
and look at other ones, they're all the same.
If we look at the type 3s, we simply take off router.
Remember, these are now called inter-area.
And again, there's two choices here, either the prefix
or the router.
Prefix would be the old type 3s.
So these are going to be entries from other areas.
Once again, we'll scroll to the bottom and take a look at one,
and notice what we see here.
This is now being advertised by our ABR,
in this case, router 3.
And we see that this actually does include the prefix.
So this last entry here happens to be
looks like router 4's actual loopback interface just based
on the address and the prefix length.
But you can see that this is actually advertising
the same way we did a type 3.
Now, we do not have any ASPRs just yet in our topology.
So if we were to right now say router,
there actually won't be any entries.
So we'll look at this one again in a future video.
Let's take a look at the routing table just briefly.
If we do a show IPv6 route and we'll filter by OSPF,
notice that all of the next hop addresses
are the link local address of router 7, which
it's a little difficult to highlight here.
I just highlighted a few of them.
But it's the FE80::7.
By the way, another good command we
have while we're here just taking a look at this,
show IPv6 interface brief.
Just like we have show IP interface brief,
and we can see all these addresses.
We can also see here our link local addresses.
Notice by the way, that my gigabit ethernet interface
and my loopback 0 interface both have the same link
local address.
This is actually fine because, well, they're local,
they're not routable, so you can actually
use the same link local address on every interface on a router.
It's not a problem at all.
So now let's take a look at some of those new LSAs.
Let's start with the type 8.
So we'll go back to our database command
and, again, these are called link locals,
so we'll just say link.
And here we see a type 8.
Notice that what it's showing us here
is the link local address of our neighbors.
So for example, I'm on router 8, my neighbor
is router 7, so let's look up here
at the top at the advertising router is 10.7.7.7,
and look what it's telling me.
It's telling me that the link local address is FE80::7.
Now, it also happens to include the prefix address
that's on that link, so the 2001:DB8:78::/64.
It lists that as well.
But the main purpose of this is to get that link local address.
The bottom entry here is, of course,
me advertising my own into the database.
So here on router 8, we have entries for 7 and 8 itself.
But if we were to go do this exact same command on router 7,
this one has entries for 7 and 8, that's itself
and rounder 8, of course, is the neighbor.
But notice it also has an entry here for router 3 out gigabit 2
advertising its link local address of FE80::3, which,
of course, 8 knew nothing about.
So this is simply showing that again, as we mentioned,
the LSA type 8s do not have to be identical through the area.
In fact, they will not be.
It's all about local information about your local neighbors.
So let's jump back over to router 8 again, and let's
take a look at the type 9s.
So instead of link, we say prefix.
Now, notice what we're doing.
These are entries for the whole area.
Notice, for example, this top entry is from router 3.
And it's telling us about the three prefixes
that are connected to router.
We have our entry from router 7 and if we scroll down
a little bit and then back up so we can see the whole thing,
we can now see that it's router 7 telling us
about its 4 prefixes.
So this is, again, the equivalent of the information
that we used to get in type 1 and type 2 LSAs
in OSPF version 2.
This information would be the same in the whole area.
In this video, we took a look at the new LSA types, type 8
and 9, that are used to advertise the link
local information for our neighbors
in the case of the type 8 and, of course,
all of the prefixes in the area tied to the router
ID in the case of the type 9.
We also jumped into the command line,
took a look at some of these in the actual database,
including the changes to the type 1.
We saw that although renamed, the type 3
was pretty much the same as it was in OSPF version 2,
just again renamed.
And then we also took a look at the type 8 and the type 9s
and we saw how the type 8s actually
don't have to be the same in the entire area,
and in fact, as we saw, they won't be.
I hope this has been informative for you.
And I'd like to thank you for viewing.