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So the first thing we want to do before we actually
start implementing IS-IS is we want
to plan out what we're going to actually do.
Now, this is true of most things that we
want to deploy on our network.
So this is, of course, certainly not unique to IS-IS.
However, IS-IS does have a few things
that we want to think about as we're getting ready to roll it
out and deploy it, and that's what we're going to try
and focus on in this video.
So let's jump in and just take a look
at a few of the fundamental things
we want to make sure we have planned out,
and then we'll jump over to our topology diagram
and take a look at what we're going to be
building throughout this skill.
So again, let's start off with some of those basic things
that we want to make sure we have in place.
So we do have a few basic steps that we
want to plan when we're doing our IS-IS deployment.
The first here is to plan our area and IP designs.
Now, the main point we're looking for
is that our area and our IP design
really has to follow each other.
Because, remember, we can only summarize at area boundaries
in IS-IS, much like OSPF.
So that means that where we can summarize
has to follow what we can summarize.
If we can't summarize properly at our area edges,
then it's not going to be a very good fit.
Now, something else to keep in mind about the area numbering
here.
We have to make a decision.
If we want to use real or readable area numbers.
And simply what we mean by that is let's say, for example,
we wanted area 10.
Well, we could do that as area 10
or since this is technically hexadecimal,
we could make this area A. So we really
have to decide which one we want to do.
Technically, area 10 should be A. However,
it's probably a little more readable and understandable
for people if you say area 10 for it
to actually show up as a 10 when we're
looking at things like our database and things like this.
So generally speaking, I personally
prefer to go with the readable design.
So if I want area 10, I'm going to make it
a 10, rather than the technical A. That's
what 10 really would be in hex.
But again, it's just a personal preference,
and you can do whatever works in your environment.
The next thing we have to do is design the backbone.
Keep in mind that the backbone is
all of our level 2 connectivity, and it must be contiguous.
There has to be complete level 2 connectivity
through the entire environment.
We also have to come up with some sort
of a net addressing scheme.
Again, the recommendation is to make these unique
through the entire environment.
Although, technically, you could do the same net number
in different areas.
It's really not recommended.
And then we want to plan where we want our passive interfaces.
In a future skill, we're going to talk
about some more advanced IS-IS features,
and one of those things is called prefix suppression.
And not to give all the secrets away right up front,
but prefix suppression and passive interfaces
sort of go hand in hand.
So we want to make sure that we actually
set up our passive interfaces correctly from the beginning
so that if we do want to use something
like prefix suppression in our design, well,
it'll actually work properly because we set up
our passive interfaces correctly to begin with.
So these are some things we probably
want to keep in mind before we start our IS-IS deployment.
But during the deployment, we have a couple
of steps we need to follow as part of the deployment as well.
The first step here is just to complete
the planning steps, which is just
everything we just did up here.
So we, again, need to plan out the deployment with things
before we start.
But when it comes to the actual deployment on the devices
themselves, the next thing we have to do
is enable IS-IS on the router.
Then we have to configure that net number
that we designed as part of our deployment strategy.
We have to enable IS-IS on the appropriate interfaces
and, again, if required, set them to passive
if that's what we need to do.
Then we need to configure the appropriate router level, link
level, and network type.
So again, for the level and the link level
here, again, we would be talking about
whether this is going to be an L1 or an L2 or both.
And for the network type, of course,
this is either going to be LAN or point-to-point.
So we need to configure the router appropriately
for the level, the link level, and the network type.
So now let's jump in and take a look
at the topology of what we're actually going to build.
So for this skill, we will be using IS-IS topology 1.
And some things to look at here.
First, we can see that we have a bunch of different areas.
So we have area of 100 here, which is sort of our core area.
We have area 10 over here on the right, which also
includes quite a few routers.
And then we just have a few single router areas.
We have an area 20 down here and an area 30 up here.
We can also see all the different interfaces here
that are going to be involved in this discussion.
Now, we may not deploy our level 1, level 2 exactly like this.
However, at a bare minimum, we're
going to have to have level 2 going from router 9
to router 2, from router 2 to router 1, from router 1
to router 7, from router 7 to router 8.
That's the bare minimum that we're going
to have to have our level 2.
Now, realistically, we will actually
build in some redundancy and things like that.
So we'll actually be implementing level 2
on more than just these links.
But from a bare minimum perspective,
this is what we would have to have.
Also, you want to make sure that we know what type of networks
we want to run.
So for example, most of these links can be point-to-point.
We can look at that as our default.
They're not going to default to that;
we're going to have to change it.
But we can use point-to-point as the default
because we only have two multi-access segments.
One of them is the link right here
between router 1, router 6, and router 7.
This is a multi-access segment, so this
will have to be a LAN segment.
Also, over here, between routers 2, 4, and 5,
this is also a LAN segment.
Now, on this side, the underlying switch
is not actually shown because it's not really
a relevant part of the topology.
However, there is a switch underneath this connection
here if you want to draw it in there.
It's just not shown on the logical diagram here.
So this is a multi-access network,
so we'll deal with that as we go through our configuration.
So, again, most of our connections
here can be point-to-point, but we
do have these two segments that are
going to have to be broadcast, or LAN, network type.
So in this video, we jumped in and just took
a look at some of the things we need to think about and design
as we're getting ready to roll out our IS-IS deployment,
as well as the steps that we have to take
to actually do the deployment.
Then we took a look at what we're
going to be building throughout the rest of this skill
as we go through the upcoming videos.
I hope this has been informative for you,
and I'd like to thank you for viewing.