Migrating to IPv6
Table 10.6 lists IPv6 Tunnel Commands and their meaning.
TABLE 1 0 . 6 IPv6 Tunnel Commands
Command Meaning
(config)#ipv6 unicast-routing Enables IPv6 on the router
(config)#interface interface Chooses your first interface
(config-if)#ipv6 address ipv6_address mask Sets the IPv6 address on the interface
(config-if)#ip address ip_address mask Sets the IP address on the interface
(config)#int tunnel 0 Chooses the tunnel interface
(config-if)#ipv6 address ipv6_address Sets the IPv6 address on the tunnel
(config-if)#tunnel source ip address Sets the source IP address
(config-if)#tunnel destination ip_address Sets the destination IP address
(config-if)#tunnel mode ipv6ip Configures the tunnel mode to be used
I certainly have talked a lot about how IPv6 works and how you can configure it to work
on your networks, but what is doing that going to cost you? And how much work is it really
going to take? These are good questions for sure, but the answers to them won’t be the same
for everyone. This is because how much you end up having to pony up is highly dependent
upon what you have going on already in terms of your infrastructure. Obviously, if you’ve
been making your really old routers and switches “last” and therefore have to upgrade every
one of them so that they’re IPv6 compliant, that could very well turn out to be a good-sized
chunk of change! Oh, and that sum doesn’t even include server and computer operating systems
(OSs) and the blood, sweat, and maybe even tears spent on making all your applications
compliant. So, my friend, it could cost you quite a bit! The good news is that unless you’ve
really let things go, many OSs and network devices have been IPv6 compliant for a few years—
we just haven’t been using all their features until now.
Then there’s that other question about the amount of work and time. Straight up—this one
could still be pretty intense. No matter what, it’s going to take you some time to get all your
systems moved over and make sure things are working correctly. And if you’re talking about
a huge network with tons of devices, well, it could take a really long time! But don’t panic—
that’s why migration strategies have been created to allow for a slower integration. I’m going
to show you three of the primary transition strategies available to you:
The first is called dual stacking, which allows a device to have both the IPv4 and IPv6 protocol
stack running so it’s capable of continuing with its existing communications and
simultaneously run newer IPv6 communications as they’re implemented.
The next strategy is the 6to4 tunneling approach; this is your choice if you have an
all-IPv6 network that must communicate over an IPv4 network to reach another IPv6
network.