IPv6 is Routable just as IPv4 is.
This means that static routing and dynamic routing protocols can still be used
Ospf has even had an upgrade to support IPv6, and we'll see how that works.
very soon. Let's start
by configuring a few simple static routes.
These are very similar to IPv4, so it should feel very familiar to you.
Step one is to enable IPv6 routing on the router.
Some Cisco routers have this enabled by default, and some don't.
We use the IPv6 route command,
followed by the Destination Network and the next hop IP
It's the same idea if we want to add a host route.
The only difference is that the prefix length is 128 bits
We can easily add a default route too. In IPv6,
::/0
is the default route
and of
course floating static routes are still available.
These are backup routes that have a higher metric than any dynamic
routing protocol
We look at the routing table.
We show IPv6 route.
Please understand that this is an entirely different routing table to IPv4.
We can have both, but they're independent of each other.
He's an advanced tip.
We don't strictly need to use global unicast IP on point to point links.
The alternative is to use link local addresses only
if you want to do this,
Don't configure the interface with an IPv6 address
instead, just configure the interface with the IPv6 enable command.
Unfortunately, there are drawbacks.
It's harder to monitor and troubleshoot interfaces that are configured
this way.
In another part of this series we covered Ospf.
That was Ospf version two, the most popular version of Ospf.
The downside is that IPv4 only
when IPv6
was created, Ospf needed to be updated.
The result was Ospf
version three which can be used with both IPv4
and IPv6 at the same time.
Or you could use Ospf version two and Ospf
version three side by side if you want to.
Now don't panic.
Nearly all of the Ospf concepts you've already learned still apply.
There are still neighbors areas hello messages, timers, and so on.
In fact, Ospf version three won't even be heavily tested in the CCNA exam,
but I feel it's too important not to give it a good mention.
The main difference is in the configuration.
The confusing part is, on a Cisco router,
there are two completely different ways to configure Ospf version three.
The old method is very similar to the one you already know.
We just use IPv6 router ospf ten to start the process
and then enable ospf on the interfaces.
It was done like this when it was common to use Ospf version
two for IPv4 and Ospf version three for IPv6.
In the
newer way, Cisco added address families
other routing protocols like BGP, use them too. An address
family just refers to the protocol that we're configuring.
In our case, this is IPv4 and IPv6
address families allow us to configure ospf to support
both versions of IP at once.
Let's try out this new method of configuration.
R2 is already done so we're going to configure R1.
This is fresh config, so we'll need to enable
IPv6 Unicast routing once again
as normal we have to start the process and assign a process number.
If we want to apply special configuration to areas such as authentication,
we can do that here.
We won't bother with that at this time.
We should also change the reference bandwidth.
This is measured in megabits per second
and of course the router id
notice that it's still in IPv4 format.
Remember that this technically isn't an IP address.
It's a 32 bit number that just happens to look like an IP address
in Ospf version three.
We don't use the network command anymore.
Instead we enable Ospf on interfaces.
Here, we're adding this interface to Ospf
Process ten in Area zero.
This will enable Hello messages and advertise
a network on this interface
back under the Ospf Version
three process, we can try out address families.
IPv6 Unicast will be our address family
IPv6 Multicast is another option.
We'll now advertise a default route
as this is in the IPv6 address family it will advertise the IP6
default route.
This won't affect IPv4 in any way.
Looking at the IPv6 routing table, now
we can see the Ospf routes that R2 is advertising
it's likely that you've noticed something interesting
about Ospf routes
in this lab
we have 4 routers in a square shape topology.
Each router has two loopback interfaces and two links to other routers.
You need to allocate /127 networks to the links
between the routers and /64 to the loopback.
Then you need to configure Ospf version
three on all four routers.
That brings us to the end of our IPv6 collection of videos.
In the next section, we're starting to look at network architecture
which in my opinion, is one of the most interesting topics.