And preparation for deploying OSPF version 3 for IPv6. Let's take a look at our
topology.
So this topology supports both IPv4 and IPv6. And this number here is here in
red that is our
subnet number. And what I'm circling there is for IPv4, but I'm also using the
same exact subnet
in the world of IPv6 as well. So all the prefixes for IPv6 begin with 2001, DBA
,
6 and 8, 3, colon X where X is that number. So here's the 12 network 13, 34, 24
, and down here WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
, and down here
to the 35, 57, 48, 46, 68, and so forth. And then down here it would be subnet
7, and over here
it would be subnet 8 for IPv6. So all the IPv6 addressing is in place for this
topology already,
but what is not in place is the OSPF version 3 for the address family for IPv6.
So let's do a quick
review about some of the basics regarding IPv6. And if you haven't worked with
IPv6 for a few minutes
or a few hours or a few days or weeks or years, it might be a great refresher WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
or a few hours or a few days or weeks or years, it might be a great refresher
as well. So as far as
addresses go, we have global addresses. And those begin with 2000 through 3FFF.
So if we see an
IPv6 address starting within that range, that represents a globally routable IP
v6 address. Then we
have link local addresses, which begin with FE80. So if you see that, that's a
link local address
that the router can use, but just for that local segment, and link local
addresses are not globally
routable. And then we have multicast addresses as well, which begin with FF. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
routable. And then we have multicast addresses as well, which begin with FF.
Now when configuring the
SPF for IPv6 on these Cisco routers, there's a few options. We can use the
legacy method, which is
IPv6 router OSPF, and then a process ID number. And that would be the legacy
way of doing it, but even if
we configure it in the older method, this legacy method, and do a show IP
protocols, it's still
going to show that it's OSPF version 3, although this is the older way of
implementing it. And what
we're going to do in this set of videos is we're going to focus on the more
current way of doing it.
And that is with literally a routing process known as OSPF B3, which can
support IPv6, and also WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
support IPv6, and also
support IPv4 at the same time. So for configuration, we're going to configure
OSPF version 3, that
flavor, the current flavor of it, with the address family for IPv6. Now with OS
PF version 3,
there are LSAs, link state advertisements that are used, and a lot of them are
very similar as we
had with IPv4 OSPF. So we have LSA type 1, which is a router LSA, generated by
our routers. So that's
very similar between IPv4 and IPv6. We also have LSA type 2, which is generated WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
very similar between IPv4 and IPv6. We also have LSA type 2, which is generated
by the designated router
for a given segment. And actually, let me adjust these columns. And actually,
let me go ahead and make
another column here. I'll put the name of it, we're here on the name of the LSA
, and then we'll go
ahead and put who generates it to the right of it. So the LSA type 1 is the
router LSA, and is generated
by each of the routers respectively. And the LSA type 2 is the network LSA, and
just like an IPv4,
that's generated by the designated router for a given segment, where there are
two or more OSPF
speakers connected to that segment. Then we have LSA type 3, and in the world WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
speakers connected to that segment. Then we have LSA type 3, and in the world
of IPv6, the LSA type 3
is very similar to the LSA type 3 in IPv4, but it's given a different name. It
's called the
interarea prefix LSA. And in IPv4, we called that a summary LSA, and that's
generated by the ABRs.
So for example, this network right here, the 2001 DB868312 network, which is in
area 0, is that
gets advertised down to area 1. That's going to be sent by the ABR here, as an
LSA type 3, which in
the past was called a summary LSA with IPv4, and now it's called an interarea L WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
the past was called a summary LSA with IPv4, and now it's called an interarea L
SA with IPv6.
Still a type 3, still providing the same functionality. There's also the LSA
types 4 and 5, which
deal with external routes that have been redistributed into the OSPF routing
domain. And there's also
a very similar to how they did with OSPF for IPv4. So the type 4 describes how
to reach the ASBR,
the autonomous STEM boundary route that we talked about in the previous skill,
and the LSA type 5 is
the external route that we're advertising, meaning that route that was redist
ributed into OSPF
from some other source, from a static route or a different routing protocol. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
from some other source, from a static route or a different routing protocol.
And although there's
a few additional LSA types, specifically for OSPF version 3, let me point out
two more. That's an LSA
type 8 and an LSA type 9. And these are unique to the IPv6 implementation of OS
PF with OSPF version 3.
The LSA type 8 is describing link local information and additional options that
they may have regarding
the individual links are connected to. So the link local addresses are the ones
that begin with FE80,
as we talked about earlier. And then an LSA type 9 is going to carry intra,
meaning within the area, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
meaning within the area,
prefixes, which is a fancy way of saying the networks. So for example, here in
area 1, with the 2001
DB86M8335 network, and the 2001 DB86M8357 networks, there'd be LSA type 9s to
describe those networks,
and those in state in the area. As far as the router IDs, that's the same as it
was for IPv4.
The router ID is a 32-bit address, which looks a lot like an IPv4 address.
However, it's just a 32-bit
identifier for the router, and it's determined the same way it is with IPv4's WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
identifier for the router, and it's determined the same way it is with IPv4's
OSPF. If there's a hard-coded
router ID that takes precedence, if there's no hard-coded router ID in the
routing process, then it's
going to use the highest IPv4 address on any loopback. And if you don't have
any loopback interfaces with
IPv4, when OSPF comes up, you'll then go ahead and use the highest IPv4 address
on any other interface
if you don't have any loopbacks with IPv4 addresses. So that process, we're
going to how it picks the
router ID is the same in every flavor of OSPF, for both IPv4 and IPv6. Also, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
router ID is the same in every flavor of OSPF, for both IPv4 and IPv6. Also,
the rules with OSPF
version 3 for IPv6 regarding becoming a fully adjacent neighbor. Those are also
extremely similar to
IPv4. So a couple of skills ago, we talked about some of the basics regarding
OSPF and neighbor
jacencies, and we used the acronym of stamp, STTAMP. So among the things that
would need to match
between two routers for them to become adjacent, fully adjacent with OSPF
version 3 for IPv6,
they need to agree on the subnet that they're both connected to. They need to WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
they need to agree on the subnet that they're both connected to. They need to
agree on the timers,
including the hello and dead interval timers. They need to agree on the network
type. For example,
as a broadcast network, our point-to-point network. And most of the time, if we
agree on the network type,
that's also going to take care of our timers issue, unless we've tweaked those
timers separately.
It's also going to help in identifying whether or not we need a designated
router for the segment.
So in a point-to-point network, I care between our four and our six. It's a
serial link, and the
network type is going to be point-to-point, no DR needed. On the ethernet
network here between our two
and our four, because it's a broadcast-based network by default for ethernet, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
and our four, because it's a broadcast-based network by default for ethernet,
and they're both
expecting there to be a DR. So when they show up on the network and there's one
, they'll go ahead and
decide who's going to be the DR. And then one of these two devices will be the
designated router for
this segment, and the other router will be the backup designated router. And a
third router, if we
add it there, would become the DR other. Another item that needs to be agreed
to is the area, and not just
the area number, but also the type of area. Is it a normal area, or is it a
stub area? So the two
neighbors need to agree on the area type and the area number. They also need to WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
neighbors need to agree on the area type and the area number. They also need to
agree on the Mtu,
the maximum transmission unit, and the p is to remind us of password, now what
that really is,
is authentication. So the two routers need to agree on the authentication, and
what type of
authentication we're using, and also the keys involved for that authentication.
So in troubleshooting,
just think of STT AMP as a reminder of those elements, which you need to match
if we want to
get full adjacencies. So just like with IPv4, R3, because it connected the
backbone in area 1, it would be
an ABR, once it's configured with interfaces in both areas, and over here on WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
an ABR, once it's configured with interfaces in both areas, and over here on
our four, once we
configure it with interfaces in area zero and in area two, it would also act as
an ABR. Now the
cool thing with that is that we can do the same types of filtering and summar
ization as we did with
IPv4. So if we want to take all the routes, for example, from area zero, and
summarize them as they're
being advertised down to area one, we can do that here at this ABR, or if we
want to take these
routes in area two and summarize those into one or more summaries as we WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
routes in area two and summarize those into one or more summaries as we
advertise those as LSA type
threes up here in area zero. Once again, at the ABR, we can do that summar
ization. And we also have
the option if we choose to to create stub or totally stubby areas, and that's
again done by having
all the routers in an area agree that it's a stub area, and for a totally stub
by area where we're
not advertising the LSA type threes down, we simply configure the area border
router, simply use the
option of no dash summary, which restricts the LSA type threes from being sent
down into this area
with the exception of the LSA type three, which is the default route, which it WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000
with the exception of the LSA type three, which is the default route, which it
'll advertise by default,
once we have this setup as a stub area. So with that overview in mind in our
next video,
let's begin to put in the configuration for IPv6 OSPFE3 based on this topology
diagram and verify
that it works. So we'll do that in the next video and I'll see you there in
just a moment.