[music]
Okay, in this section we're going to be looking at using EIGRP for IPv6.
Just like regular EIGRP this is fairly simple, fairly straightforward.
We do have two different ways we have to look at configuring this though,
so I'll sort of do a mix-and-match on the routers as we go,
to see the two different ways to configure it.
We'll be, as always, sticking with our base topology for now.
We're going to be running EIGRP between routers 3 and 6 and 5 and switch 4,
just to give us a little area there to run EIGRP to do a
little bit of messing around.
The other thing to note here is I do have two segments here,
VLAN 456 and VLAN 344, that are running link local only addresses,
indicated by those little dots there.
I know it's a little hard to see, but there's little dots there on
the interfaces that indicate that they are link local only.
And I did this just to show that for the routing protocols, it doesn't matter.
You can run completely link local addressing, because all the neighborship
is done on link local addressing as well as all the routes use link
local addresses for their next-hop.
So the basic way this works is we're just going to be adding a new
address family to EIGRP.
It can be run in either legacy or named configuration.
Legacy or traditional, whatever you want to call it.
If we're going to run it in a VRF-- and we will see this when we get to our MPLS lesson.
I'm not going to get into a VRF in this particular lesson,
but I will show you the syntax as to where you would do that.
But we're not going to actually set up a VRF right now.
We're just going to do regular EIGRP to begin with, but you do have to use named mode.
And you'll see also when we do legacy mode that this is going to cause the creation
of the global process-- sorry, not cause it, actually require it.
We're going to have to do that, and on some code you actually have
to do a no shut under that global process.
On this particular code we don't have to, but nonetheless some code you do.
And if you do named mode, you get this automatically on all the IPv6 interfaces.
And, again, these are just some little notes I wanted to put on here.
Of course, we're going to jump to the command line and look at all of this.
So let's switch over here - and I think I'm on switch 4 from
the other day, so we'll just switch over here to router 3.
We'll just start here. And on router 3 we will start with just doing legacy mode here.
So, on router 3 we will say interface fa0/0.36, ipv6 eigrp 100.
That's really all there is to it.
You have to create the global process.
If I said do show ipv6 eigrp interfaces,
we'll find out that it's actually not running anywhere yet.
All we have to do is say ipv6 router eigrp 100, and now it's running on the interface.
If you look back at our RIP lesson, you'll realize all we literally
did was turn on RIP under the interfaces. Now, is there a IPv6
router RIP, you know, RIPv3, whatever you named the process?
We didn't really go in there because there's not a whole lot to configure
until we get into redistribution.
If you want it to [weight?] timers and things like that, of course they're in there.
That's the same thing here with EIGRP.
If you take a look at what's actually here,
these are just things that are going to affect the overall EIGRP process.
Again, it's very, very similar to IPv4.
There's really not much difference here.
We'll get to some of these things as we go into redistribution and stuff like that.
But this is where you would go if you wanted to do a passive interface,
control or distribute list [to?] actually filter the routes.
These are all the same commands that you would use for traditional
IPv4 route filtering and route manipulation and so on.
There's really not much difference here at all.
So let's hop over to router 6.
Just to show you, I'll use router 6 in named mode.
Named mode with EIGRP is sort of a newer format.
This is where they're headed with it, and you're going to say here, router
EIGRP and then give it a name.
We'll call it IPv6.
It doesn't really matter what we call it.
It's a named process. Then you just hit Enter.
This drops you into EIGRP named configuration mode.
From here, if you're new to named mode, there's not much you're going to do.
As you can see here, we can go into an address-family,
set a command to the default of course, exit the structure, negate something -
so take out something.
You can enter a service family.
We're not going to get into those in this course, but that's another
option that's available there.
And of course, you can shut down the whole process.
As you can see, there's really only one choice we're going to do
at this point, which is address-family.
Now we can support either IPv4 or IPv6 from here.
A couple things that are nice, all your EIGRP configuration mode
now moves here in named mode.
It's under router config mode for both IPv4 and IPv6.
You're not typing router eigrp 100 ipv6 router eigrp 100 and having
two separate configuration sections.
It's really all just right here under named mode.
Now, of course, what we want to say for right now, since we're not
here for IPv4 is, we want to type ipv6, and then you have no choice
but to say an AS number.
Notice like hitting carriage return, not an option.
This is where, if we were running a VRF,
and we would call it CUSTOMERS or something like that,
we could then put the AS number.
This would fire up IPv6 inside the VRF CUSTOMERS and assign it an AS number.
If you're not real familiar with VRFs,
these are used mostly in regard to MPLS, but certainly for lots of other features as well.
The basic idea is creating multiple routing tables on a router and
therefore separating routing tables and therefore traffic.
Look at it as a form of virtualizing the router.
It's what it's called, virtual router and forwarder.
We'll get to those.
We'll do it, of course, in the context of MPLS when we look at IPv6
over MPLS later in the course.
So, address-family ipv6-- this is just sort of a little syntax thing
that I think's a little bit interesting.
If you look at the command here, the next thing would be AU for Autonomous System,
and then we say AS 100.
That's fine. But, what if I said, since everybody calls it this,
AS, and I hit ?, it says unrecognized command.
Now again this kind of little detail here,
just so you understand, this kind of little thing can vary code to code.
This is just sort of an interesting behavior on this code.
Whatever code you're on may not act exactly like this,
but the interesting thing is we say AS 100 and it takes it anyway.
And my guess is they probably did a lot of testing as they were developing this,
then kept typing AS 100 by mistake or something and realized,
we probably better just make that work because people are going to do it.
And the funny thing is, is I think I was doing it for quite
some time before I realized, you know, that's actually not the shortening of that command.
It should be AU and then maybe tab it out or just go from there - not AS.
But it takes it anyway, which sort of is a nice thing, since that's
what I was in the habit of typing and was doing it anyway.
Okay, now, the next part with named mode,
once you're in the address-family and the AS number you want to be in.
Couple things to note.
First, if you look at our command prompt there, EIGRP has already come up.
There it is. We already have a neighborship with router 3,
and if I were to say, do show ipv6 interface-- and it did not want just interfaces,
eigrp interfaces, a little more detail than we needed on that other one.
But you can see here, we are automatically running EIGRP on all of our interfaces.
In this particular case, on router 6,
we didn't want to be running EIGRP on his gigabit 0/1 interface.
So what we need to do from here is take a look at the subconfiguration modes.
Again, I'm not going to go over shut no default,
every time we go into something, or of course help.
Exit address-family, also I hope, fairly obvious here.
But there are a few commands, eigrp for example,
and in here you can say that it's a stub,
you can set its router ID for external eigrp routes.
You can also, back here, set up the metric.
So, metric weights, of course, is to set the K values,
which, generally speaking, we shouldn't really have to mess with in
EIGRP, unless you wanted to bring in reliability or load into the value,
and/or change the weighting factor of bandwidth versus delay.
Now, the other thing you might need to do is,
if I back out of here-- and I don't think we're going to have any routes just yet.
Do show ipv6 eigrp topology.
All we have right now is the stuff that we are locally putting into the database,
but what we can do-- and we're not going to leave it
this way but that's okay, at least for now.
We can do-- you know what, let's go to router 5.
Let's bring up router 5 awhile and we'll do named mode on him as well.
I'm actually starting to lean more and more and more towards
just doing named mode constantly, but we do still of course need to
look at the legacy as well.
So router eigrp, and it doesn't matter what you call it,
we can call this one eigrp. I'm not going to.
It is a local name.
However, as we get into configuring and moving back and forth between
devices, it just gets, of course, very confusing to remember what you named it everywhere.
So I will call this one IPv6 as well. Address-family ipv6 unicast
for AS 100. And their neighbor with 456 comes up, which means, do show ipv6 eigrp topology.
We should now have some routes from the other side.
The main reason I'm bringing this in here to show you is I want to
show you these metrics, because if you say do show ipv6 protocol,
what you're going to find - two things - is the RIB scale and the metric version.
The metric version defaults to 64-bit.
These are what we refer to as EIGRP wide metrics.
This is being done, of course, to compensate for newer, faster links
that are coming out, so we're moving towards a wide metric.
By the way, it's just a little side note here.
With the wide metric, if you're in that habit like so many people are,
of, when you redistribute into EIGRP, just saying metric 1 1 1 1 1,
don't do that anymore, because with wide metrics you've got to remember,
that first number you put in is bandwidth in kilobits per second.
When you type 1, you're telling it that it's 1 kilobit per second,
which is like, I don't know, the worst possible route imaginable.
For wide metrics it'll actually say, I forget the exact terminology,
maybe we'll do it here later.
It says something like the feasible distance is infinity or maximum
or something along those lines. I think it says infinity.
But the fact of the matter is, it won't use the route,
so you can't just do the 1 1 1 1 1 like you used to.
But the main thing I want to show you here is what the rib-scale
and the metric version are for.
There's not too much else that's changed.
We pick up a K6 value. I'm not going to get into, here, all the detail on what that's for.
In this version of code it's not being used, the K6 just stays at 0.
It has to do with compatibility and feature exchange.
But in this case I do want to show you these other things though.
The rib-scale, what this is for is, 64-bit metrics don't fit in the routing table,
so if I said do show ipv6 route,
and look at these metrics - these are all connected.
We'll pick on 36. We'll just pick on VLAN 36 here.
If we look at the one up here in our topology for 36,
notice the value versus our routing table.
The way this works is we simply take this number and we divide by the rib-scale, 128.
If you were to take 19660800, divide by 128, you get this number.
That's what it puts in the routing table.
Again, this is done simply because 64-bit metrics do not fit in the routing table.
If you're going to stick with 64-bit metrics, which would be the recommendation, of course,
then a lot of people look at this and go,
okay, so you said three minutes ago that we're going with these to
support the new higher-speed interfaces.
Then we're taking this better-scaled metric and we're dividing it
by 128 to put it in the routing table, so then
aren't we just losing the granularity of the larger number?
The answer is yes, you are.
You're losing the granularity.
However, the actual decision on the best route happens in the EIGRP
topology table when EIGRP chooses its best path.
My point is, I really don't care if it puts it in the routing table with a 4
or a 100 or just any random number.
It really doesn't matter what's in the routing table, because once
it's in the routing table from EIGRP, admin distance, of course,
is going to kick in and determine is it going to be EIGRP,
is it going to be RIP, is it going to be OSPF,
who's putting the route in the routing table?
But once admin distance has kicked in and it's been determined that
we're going to be using the EIGRP route, I really don't care what that metric is.
I mean look at these two.
Here's RIP with a metric of 2.
Again, who cares?
The metric is only used within the routing protocol for it to choose its best route.
Once that decision's been made, I really don't care what's in the routing table here.
It really makes no difference.
Right here we have 153600 right next to a 2,
and it doesn't matter because they're from two different routing protocols,
and since that's the only way I'm learning them right now,
then that's the one that wins and goes in the routing table.
This whole metric scale, the rib-scale thing,
it really sometimes freaks people out a little bit, especially if
you've not actually seen this, because you're looking at this up here,
looking at the topology table, and then looking at the routing table
and you're like, okay, where did that number come from?
The fact of the matter is, it just scaled it down. That's all.
If for some reason - and I do not recommend this, but I
like to show it, just completeness, just so everybody's seen it -
if you needed to, you could say metric version 32bit.
Then when you say do show ipv6 eigrp topology--
it didn't scale them down yet.
Give it its chance to sync there.
I'm like, those aren't right.
There we go. It will scale these down.
Then you say, do show ipv6 route eigrp.
Then you can see these match up now.
So 36 is 30720, 30720.
That does not mean, by the way, that they're going to be the same
numbers as they were above, because a lot of people then look back
at what we did a minute ago and say, wait a minute, those numbers don't match.
That's because this number before was a scaled down - divided by 128 -
of the 64-bit metric.
This is flat-out a 32-bit metric.
It's a whole different scale.
It doesn't mean that it's going to be half the other value because
it's half the number of bits.
It doesn't work like that.
If you wanted to, you could back this off and go back to using more
traditional methods, so to speak.
Traditional, like if we went up router 3 and said do show ipv6 eigrp topology,
he would be using the old method,
and he would have those older numbers, see like 30720.
In fact, I don't think you can even--
yeah, see, it doesn't even support changing it.
Remember that router 3 is running legacy mode.
I'm not saying that there wouldn't be code that does support it, but this code doesn't.
And by the way, in case you're wondering why I hit question mark,
looked at this, and then went ahead and tried to type it anyway--
If you go back to where we were changing it a minute ago on router 5 here,
I'm going to change it back.
If you say metric version, notice that the metric here looks exactly the same.
It's slightly different numbers. You've got rib-scale and weights.
Version is not here either,
but if you say version 64bit, it takes it.
Do show ipv6 eigrp topology, let's give it a second to reset before we do this.
There we go, [soft?] reconfig, hit Enter, and we're back to the regular numbers.
So it's really not recommended to change it, that's sort of why Cisco hid that command.
They don't want you changing it, I would not change it,
but just to show you how the whole rib factor and the wide metrics work,
there you go. By the way, just as a side note,
it's not really our topic here, but as a side note, remember that
EIGRP for IPv4 with named mode does this exact same thing.
Other things you can do from here is-- there's not really a whole lot.
Like I said, we can adjust some of the timers and you can put in manual
neighbors and stuff like that here, but the main thing is we have
two other sub-configuration modes.
One of those is af-interface.
One of the big things that changes with named mode is, none,
and I mean zero, of our config goes under the interface now for EIGRP.
All those commands such as summary address,
and turning off split horizon, and all of those kind of things that
went under the interface, are now under the router config under the af-interface command.
You would go into any interface, so in our case we could say interface
fa0/1, if you remember.
I'm sorry, not on router 5 though.
Let's switch over to router 6 actually.
So let me back out of that before I mess something up on router 5.
It was actually on router 6 where we were running-- let me go back to the command.
Where we're running EIGRP on gigabit 0/1, and if you look back to our
topology diagram, we're not supposed to be.
We say af-interface - yeah, I know it's not complete - gigabit 0/1.
There's actually two commands you can do here.
Just from a practical standpoint, I've not really come up with a
good difference between them.
Let me show you what I mean by that.
If I switch over to router 5 and I say do show ipv6 route for eigrp,
he should have subnet 69, which is the link going up to switch 3.
Just as a reminder here, because I know you're not that familiar with it and
we haven't looked at it for a little while here. If I switch back over
to the topology here,
we're talking about this link up here at the top between router 3
and router 6. That's the link we're talking about right now.
And if we take a look at this, I don't need to be running EIGRP on that,
so we come back to router 6 and we say shut.
We shut that interface for the EIGRP process,
and then we say, do show ipv6 eigrp interface,
and it shows that we're not running it on gigabit 0/1 anymore.
So, that means you're not sending out hellos or any of that kind of stuff.
You would not bring up a neighborship,
but if you go back here to router 5, it disappears.
This is really the difference between a shut and a pass.
If I go back to router 6, maybe I did want that network in EIGRP,
I could say no shut, pass, and if I did that,
do show ipv6 eigrp interface, it keeps it off the list.
So a lot of people look at this and they're like,
well what's the difference between a shut and a pass?
That's what I'm trying to get to here.
So if I do that and I go back to router 5, we should've picked that network up again.
Okay, there we go.
So the difference is, do you want that advertised into the routing process or don't you?
That's the difference between the shut and the pass.
Now, again, we don't want it in there at all because we're going
to use it for other fun stuff later.
I'm going to say no pass and then I'm going to say shut again.
I just wanted you to see the difference between those.
Now, once again, here under the interface,
this is where you would now put all the things that you would normally
put for EIGRP under the interface, but now they go heon't you? That's the difference between the shut and the pass. Okay, now again, we don't want it in there at all because we're going to use it for other things. We'll do other fun stuff later. So, I'm going to say no pass and then I'm going to say shut again. But I just wanted to see the difference between those. Okay, now once again, here under the interface, this is where you would now put all the things that you would normally put for EIGRP under the interface. But now they go here. Okay, so just as a case of discussion and again, I'm not going to leave it here, but I can say this is the interface. We're under the wrong interface right now. So, AF interface gigabit 00.456. This is the interface facing down towards router 5. I could do summary address colon colon slash zero. Okay, I get a summary reconfigured. Go back to router 5 and our routing table is going to look just a little bit different now. Okay, so again, the main thing I'm trying to show you that this is not about, you know, obviously we can't go over every detail of every routing protocol. Our focus is on IPv6 and the differences between them. So, mostly I guess what I'm trying to show you here is that it's the same. Really? Okay, we do it the same way. So, I'm going to do this versus normal mode versus IPv4 versus IPv6. This is really just named mode versus legacy mode. It really doesn't matter what address family we're in. It's just you got to remember that you're dealing with IPv6 addressing. So, when I just summarize to the default there, it's of course an IPv6 default. So, let's take that back out. I don't actually want to do it right now. But this is also where you would change hello times and of course, you know, next top, excuse me, next top behavior, things like that. So, none of the commands go on to the interface anymore. And what can really confuse people is if you say interface gigabit 00 .456, that's not right. Or you just create a whole new one. IPv6 summary address for EIGRP 100 and tell it to do colon colon slash zero. So, tell it to go ahead and create the summary address under the interface. That's what you would do in legacy config. And quick thing to note, we could go look that this hasn't happened. Or you could just go by the fact that you haven't seen a resync. Every time up here when we created a summary, we did a resync. Take the summary off. Resync. Put the summary on the interface. Nothing. Okay. We can go over to router five. We can look at this routing table. Okay. And we've picked up our 36 and our 100 again and lost our default. Okay. This is what I'm talking about when I say with named mode, none of the config goes on the interfaces. Now, the commands don't magically disappear off the interface. And I'm not going to leave that in there. Because of course, it's not doing anything anyway. Because, you know, the router doesn't know if you're going to switch over and do legacy EIGRP config. In which case, the commands would go under the interface. So, I'm just trying to point out, you know, again, this is not really IPv4 versus the USB. This is IPv6 here. This is named mode versus legacy mode. But we're going to need named mode for IPv6. Especially for VR apps. So, we have to move to this. Okay. So, let's go back into our named mode again. So, router, EIGRP, IPv6, address family, IPv6, unicast, for AS100. And the other thing we didn't look at yet is, oh, one more thing with AF interface, by the way. There's also an AF interface default command. And if you do that, what you're doing is you're configuring all of the interfaces. So, if I said pass, this would be like the old, you know, passive interface default. And then no pass, whatever. So, you know, you can still do those same kind of constructions. It's just that you use AF interface default instead. Okay. And one other thing too to note, one thing you cannot do under default specifically. And it's a little hard to highlight something that's not here. But if you look down here at the bottom, you don't have summary address. Okay. Up here, we typed summary address and then put in the default under the address family. See right there? Summary address. You can't do that under the default. Okay. But everything else you can configure. And this would be doing all of your interfaces at the same time. Okay. And one more quick thing about that shut in the past. I just want to make sure we're clear on something. When we went into named mode, and I don't know if anybody necessarily directly picked up on this. I did say it in the slides earlier, but I just want to make sure you got it. That as soon as we went into named mode and put in the address family, our neighbors came up. So this immediately brings up IPv6 on all of the interfaces. Okay. One last thing for now, and we will be back to this as we get to redistribution and things like that. But if I exit out of AF interface, there's also topology. And this does support multi -topology on some code. This code does not. So we just say topology base. And this is where you would do all the things related to the EIGRP topology. Okay. So again, things like maximum paths, changing the variance to do one equal cross load sharing. Putting in a summary metric. Putting in redistribution, which is the part we'll get back to. This is where you would put your distribute list. Change the admin distance. All of those things you would normally do under EIGRP global mode. Okay. So at this point, that takes care of EIGRP on router six and router three and router five. We did not do switch four. So interface VLAN. We'll just do legacy mode over here just so we have a couple. So interface VLAN 456, IPv6, EIGRP 100. And then router, whoops. IPv6 router, EIGRP 100 to create the global process. And the neighbor should come up. And there we go. Do show IPv6 route, EIGRP. And we're up and running with EIGRP. And the other thing to point out, and this is the first time we really started jumping into the routing table, is notice that all of the next hops to all of these networks are all the link local addresses. Okay. So if I were to say, you know, do trace to, let's see what should we go to. We actually have a lot of networks in the EIGRP here I don't want. We'll be with that in a minute. But let's just trace to router six's loop back here. Looking good. Looking good. Problem here. Nobody has any way to answer me. I think is what's going on here. Because I didn't bring anything on switch four into the routing process. So they have no way to get back to me. If we go to the other devices, they have no, they have no routes. So we'll take a look at some of this more. Well, you know what we could do? We could just do bring switch four's loop back in. Interface, loop back zero. Give me that other one. And then the one back out of the interface. Did I? Let's give him an actual address. Let's go to router six. To filter that, but that's okay. Oh, he still has a static default in there. We need to get rid of that. There we go. A little bit better. Okay. And just make sure we're working both ways. If we go back to switch four, he should be able to do that one that didn't work there for us. Much better. A little bit of goofy routing going on there. Okay. So that takes care of running the edge. Redistribution coming up in a future lesson here. So we're not, of course, done with the IDRP, but that's just the basics of getting it up and running with IPV six.