[AUDIO LOGO]
So for our first configuration, let's
jump in and configure redistribution
from our other protocols into IS-IS.
Now, we are going to be using a new topology for this skill.
So let's start by introducing that topology, talk
about what redistribution we're going to do.
And then, of course, we're going to jump into the command line
and make it happen.
So let's start by taking a look at that topology.
So in this skill, we're going to be using IGP topology 2.
And as we can see, this involves several different routing
protocols.
Up here between router 6 and router 10, we have RIP.
Then for this whole section down here at the bottom left,
we have IS-IS.
And it's all running a single area.
It's all running area 10.
On the top right between routers 1, 2, and 9, we have EIGRP 100.
And then between 1, 2, 4 and 5 is OSPF.
And like IS-IS, this is running a single area.
In this case, area 0.
In this video, what we're going to be doing
is configuring redistribution into IS-IS.
Specifically, we're going to redistribute RIP
into IS-IS on router 6.
And then we're going to redistribute OSPF
into IS-IS on router 1 and on router 3.
So that's what we're going to configure to get started
as we jump into redistribution.
So let's go ahead and jump into the command line.
So let's begin here on router 6.
We'll start with just a show ip route just
to verify its routing table.
And specifically, what we're looking
for is the fact that it has a few RIP routes here.
So we can clear this up a little bit by saying RIP.
And we can see that we do have three RIP routes that we've
learned so far on router 6.
Let's also verify that these routes are not on router 7.
So just to focus on one root, let's look at this
204.186.19.0/26.
And let's go over and verify that it's not on router 7.
So we'll look specifically for that prefix.
And we see that the network is not in the table.
So currently, the RIP routes are not in the IS-IS environment.
So now, let's go ahead and configure our redistribution.
So back on router 6, we'll go into our IS-IS process.
And we'll start with a very simple redistribution.
We'll simply say to redistribute RIP.
We'll go ahead and end that configuration.
And now, let's verify.
So let's go back over to router 7 and see if this has worked.
We'll simply repeat the last command.
And notice that the network is still not in the table.
Now, this is one of our caveats with IS-IS.
The default is to redistribute routes into level 2 in IS-IS.
However, all of our devices are running IS-IS level 1
since it's just a single area.
So what we're going to have to do
is we're going to have to modify our redistribution
to send the routes into level 1 instead of into level 2.
To do this, we simply go back into configuration mode.
And we can pretty much just repeat
all of our last commands.
But instead of just saying redistribute RIP,
notice that we have an option here
to specify which level the routes are going to go into.
Now, we could say level 1 and level 2.
But again, we have no level 2 in this particular topology.
So we'll simply say level 1.
Lay the configuration again.
And now, let's see if it's worked.
So back on router 7, notice that now, we
have the entry from IS-IS.
There are a few things, however, about this prefix
we want to take note of.
First is that it's an ISIS level 1 route.
Of course that's what we told it to bring it in as.
But IS-IS doesn't really have a mechanism
for keeping track of the fact that this was an external route
being redistributed.
The second thing is notice the metric
on this route, where the cost is a cost of 10.
That's of course, the cost between the two routers.
That means that the route is coming in as a 0,
which we had indicated before.
That is what the seed metric is in IS-IS.
However, there is a choice to actually
have it copy the metric out of the routing table when
it does the redistribution.
Let's go ahead and configure that and see what changes.
So once again, we'll go into configuration.
We're going to router IS-IS.
And on the redistribution line, we can add metric type.
And then we have a couple of choices here.
The one we're looking for is to say rib-metric-as-external.
And that will cause it to put the rib
metric from the routing table onto the route.
Once again, we'll exit configuration.
And let's go back to router 7 to see our change.
So we'll repeat this command again.
It's only a difference of one because it was only
one RIP hop away on router 6.
But notice that our cost is now 11.
So it's taking the cost from the rib.
In the case of RIP, of course, that being a hard count,
and bringing it in to IS-IS.
Now, we hadn't really mentioned this previously.
But why don't we go ahead and bring a connected route
into IS-IS as well?
If we do a show ip route isis here on router 7,
I can't highlight what's not here.
But we're going to bring in an 88.88.88.0, which
is big surprise, coming from router 8.
So let's hop over to router 8 real quick.
We'll start with the show ip interface brief.
And we see here that we have this loopback 88
with that network I just mentioned configured on it.
Let's bring this into IS-IS as well just
so we can see how it works.
So we'll go into configuration mode.
Again, into the IS-IS process.
We'll say redistribute connected.
And again, we'll specify level 1 because that's
all we have in our environment.
Exit configuration, and let's go back to router 7.
On router 7, we'll just do the show ip route isis again.
And notice at this time, we do have that 88.88.88.0
coming from router 8.
And again, it just looks like a typical IS-IS level 1 prefix.
If we look at more detail on this,
we could say show isis ip rib.
And look at that particular prefix.
We see that it's in our topology.
We see the majornet being 88.0.0.0/8,
which is essentially the fact that it's a class A network.
Then of course, we see the prefix itself.
And we see it's next hop, who we learned it
from, any tags, things like this.
But again, no real indication that
is from an external source.
We could also look at a show isis database, specifically
the l1 database.
And we can ask for detail for IP entries coming from R8.00-00,
which is router 8's IS-IS ident.
And again, notice even in the detail of the database output,
there's really no indication that this
is from an external source.
So just keep that in mind as a caveat in IS-IS.
Next, let's go ahead and configure the redistribution
from OSPF into IS-IS.
For that, we'll jump over to router 1.
We'll go into configuration mode for IS-IS.
Under the address family IPv4 unicast,
we'll say redistribute ospf process 1.
And again, we'll bring them into the level 1 database.
We'll commit those changes.
Exit configuration.
And one thing we could do to make sure that it's working,
we could do the show isis database.
And we'll just look at our own database.
So XR1.00-00 and do detail.
Essentially, looking at this, all
of these entries with a metric of 0
are either local to this router or are being redistributed.
So this is bringing the information into IS-IS.
So if we jump over to router 7, repeat looking
at the IS-IS routing table, we'll notice first,
it's a lot larger.
And we're getting entries from the OSPF environment.
Just for a route to focus on, notice we have the 10.2.2.2/32
entry, which is router 2's loopback.
Router 2, of course, is in the OSPF environment.
So this is a route being redistributed.
Let's configure router 3 the same way.
Go ahead and commit those changes.
And we'll verify the database here as well.
So as we can see by these entries with metric 0
on this router, it's also doing the redistribution.
Let's see if that's changed anything on router 7.
If we look at the routes again on router 7,
we'll notice that for several of these, such as our 10.2.2.2
address, we are actually now multipathing through router 1
and router 3.
Now, at this point, we could do a connectivity test.
But it's most likely not going to work because what
have we configured so far.
We have configured one-way redistribution of routes
being sent into IS-IS.
So let's hop over under router 8 and just do a ping test.
We're expecting it to fail, but just
to see how we don't actually have reachability
because the other routing domains have no idea how to get
back to the IS-IS domain yet.
So again, just real quickly here on router 8,
we'll do a ping 204.186.19.202, which
is an address up on router 10.
And of course, it fails.
Just to show you real quickly that this
is an address on router 10, notice
that it's right here on the loopback 204 interface.
It has that address 204.186.19.202.
because we hadn't looked at that previously.
In this video, we saw how to redistribute routes into IS-IS.
We saw how it brings them in with a default metric of 0.
We also saw how we can have it copy the metric from the rib
if we choose to.
So next, it would be a good idea to configure redistribution
into OSPF.
And that's exactly what we're going to do next.
Until then, I hope this has been informative for you,
and I'd like to thank you for viewing.