IPv6 OSPFv3 on Cisco IOS Router

When we use OSPF for IPv4 we are using OSPFv2. OSPF has been updated for IPv6 and is now called OSPFv3. These are two different routing protocols and in this lesson I’ll show you how to configure OSPFv3 so that you can route IPv6 traffic. Here’s the topology we’ll use:

Let’s start with the configuration of the interfaces and the IPv6 addresses. We don’t have to configure any global unicast IPv6 addresses on the FastEthernet interfaces because OSPFv3 uses link-local addresses for the neighbor adjacency and sending LSAs. Here’s the configuration:

R1(config)#ipv6 unicast-routing 
R1(config)#interface loopback 0
R1(config-if)#ipv6 address 2001::1/128

R2(config)#ipv6 unicast-routing 
R2(config)#interface loopback 0
R2(config-if)#ipv6 address 2001::2/128

Don’t forget to enable IPv6 unicast routing otherwise, no routing protocol will work for IPv6. Let’s check the interfaces:

R1#show ipv6 interface brief 
FastEthernet0/0            [up/up]
Loopback0                  [up/up]
    FE80::CE09:18FF:FE0E:0
    2001::1

R2#show ipv6 interface brief 
FastEthernet0/0            [up/up]
Loopback0                  [up/up]
    FE80::CE0A:18FF:FE0E:0
    2001::2

After configuring the IPv6 addresses on the loopback interface, you can see the global unicast and the link-local IPv6 addresses. There is no link-local address on the FastEthernet interfaces, however, so we’ll have to fix this:

R1(config)#interface fastEthernet 0/0
R1(config-if)#ipv6 enable

R2(config)#interface fastEthernet 0/0
R2(config-if)#ipv6 enable

R1#show ipv6 interface brief 
FastEthernet0/0            [up/up]
    FE80::CE09:18FF:FE0E:0
Loopback0                  [up/up]
    FE80::CE09:18FF:FE0E:0
    2001::1

R2#show ipv6 interface brief 
FastEthernet0/0            [up/up]
    FE80::CE0A:18FF:FE0E:0
Loopback0                  [up/up]
    FE80::CE0A:18FF:FE0E:0
    2001::2

Now we can configure OSPFv3:

Forum Replies

Hi Rene,
Do areas work the same way ON IPV6 as on OSPF v2?

Hi Alfredo,

The areas are still the same, basically OSPFv2 and OSPFv3 operate in the same way but there are some differences when it comes to LSAs, building the LSDB, addressing, etc.

I’ll cover this in another lesson if you are interested.

Rene

I will be interested.

Thanks

Hey,
Why we use global Unicast address? isn’t it public address? I understand when its local communication we can get away with link local address and when we require routing we use Global Unicast or Unique local, right? Can we use unique local address in above example instead of Global unicast? implied we are not going to route outside it is just going to be site and inter-site based routing, so in that case we can use Unique local?

Thanks,
AD

Also, please show how to assign a unique local address?

Thanks,

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