How to configure cisco router with IPv6

How to configure cisco router with IPv6

In this tutorial we will configure Cisco router with transition method discussed in pervious article.

Dual Stacking

This is the most common type of migration strategy because, well, it’s the easiest on us—it allows our devices to communicate using either IPv4 or IPv6. Dual stacking lets you upgrade your devices and applications on the network one at a time. As more and more hosts and devices on the network are upgraded, more of your communication will happen over IPv6, and after you’ve arrived—everything’s running on IPv6, and you get to remove all the old IPv4 protocol stacks you no longer need.

Plus, configuring dual stacking on a Cisco router is amazingly easy—all you have to do is enable IPv6 forwarding and apply an address to the interfaces already configured with IPv4. It will look something like this:

Router(config)#ipv6 unicast-routing
Router(config)#interface fastethernet 0/0
Router(config-if)#ipv6 address 2001:db8:3c4d:1::/64 eui-64
Router(config-if)#ip address 192.168.255.1 255.255.255.0

6to4 Tunneling

6to4 tunneling is really useful for carrying IPv6 data over a network that’s still IPv4. It’s quite possible that you’ll have IPv6 subnets or other portions of your network that are all IPv6, and those networks will have to communicate with each other. Not so complicated, but when you consider that you might find this happening over a WAN or some other network that you don’t control, well, that could be a bit ugly.

So what do we do about this if we don’t control the whole network? Create a tunnel that will carry the IPv6 traffic for us across the IPv4 network, that’s what.

The whole idea of tunneling isn’t a difficult concept, and creating tunnels really isn’t as hard as you might think. All it really comes down to is snatching the IPv6 packet that’s happily traveling across the network and sticking an IPv4 header onto the front of it.


configure the tunnel on each router:
Router1(config)#int tunnel 0
Router1(config-if)#ipv6 address 2001:db8:1:1::1/64
Router1(config-if)#tunnel source 192.168.30.1
Router1(config-if)#tunnel destination 192.168.40.1
Router1(config-if)#tunnel mode ipv6ip
Router2(config)#int tunnel 0
Router2(config-if)#ipv6 address 2001:db8:2:2::1/64
Router2(config-if)#tunnel source 192.168.40.1
Router2(config-if)#tunnel destination 192.168.30.1
Router2(config-if)#tunnel mode ipv6ip